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Aric
Aric, Technician
Category: TV
Satisfied Customers: 33118
Experience:  10+ yrs. experience installing and repairing TVs and A/V systems. Owner of A/V installation and repair business.
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I have a 50 inch Panasonic Plasma flat screen TV Model TH50PE700U

Customer Question

I have a 50 inch Panasonic Plasma flat screen TV Model TH50PE700U

It will not power up to display a picture. Instead it powers on, then the light blinks 6 time then repeats with a series of 7 blinks followed by a delay then again 7 blinks. I have unplugged the HTMI cables from the back and let the tv rest for a day then plugged it into a different 110 volt outlet. Same thing. And repeated this twice more - same result.
Submitted: 1 year ago.
Category: TV
Expert:  Aric replied 1 year ago.
Hello, My name is XXXXX XXXXX X will be glad to assist you. Troubleshooting what is wrong will require that I ask you for some more information. Also, please keep in kind that there may be a few minutes between replies, as I research your problem.

How long have you had the set for, and when did the problem occur?
Customer: replied 1 year ago.

TV manufactured in 2007 and was purchased new during that year.


 


Problem began when I tried to turn the TV on. Last viewing was the previous night. During that viewing the TV was on for a long period of time - 4 or 5 hours before turning off.


 


I will be wanting a board level type analysis as I may try to purchase the parts and replace them. I have worked on electronic devices including TV and monitors before. I do not have a scope, but a reliable multi-meter.


 

Expert:  Aric replied 1 year ago.
Thanks for the reply. I'd lik you to try one more thing and check the Error Code again to make sure we have an accurate code:

Please disconnect the set from AC power, then press and hold the power button on the TV itself (not the remote), for 20 seconds. After another minute, plug the set back in and press power once.

Do you have the same code?
Customer: replied 1 year ago.

Same thing - the tv has been unplugged for more than 10 hours - depressed the power switch for 30 seconds - then plugged into a 110 outlet and get a code of 6 THEN the second and subsequent codes were 7.


 


 

Expert:  Aric replied 1 year ago.

Thanks for the reply. The 6 or 7 blink code on this set indicates essentially the same thing- to check the Y Sus board for shorts. Now, in the field, it is common knowledge that a faulty Y Sus (SC) Board will also take out the SU and SD Boards, so it is the best idea to replace these boards all together. This starts adding up pretty quickly, but if you're doing the work yourself then you're saving a couple hundred dollars right there. The link below is to where you can purchase the boards for your set (although the SC is showing currently out of stock):

http://www.shopjimmy.com/catalogsearch/result/?q=Panasonic+TH-50PE700U&restrictBy[known+models]=Panasonic+TH-50PE700U

I would suggest staying in touch with Shopjimmy to locate an SC board, as they are constantly getting new boards in stock.

 

Actually it looks like they have one in stock at TV Parts Guy at the link below:

http://www.tvpartsguy.com/servlet/the-7045/PANASONIC-TH-dsh-50PE700U-Y-dsh-SUSTAIN-BOARD/Detail

 

 

If you need further assistance let me know.

If this answers your question, please rate the answer with a "GOOD" or better, as it is the only way we Experts get paid for our work, and knowledge on the site. Bonuses are welcome and appreciated!

Customer: replied 1 year ago.

SO to be clear - you are saying to replace all three boards - I can agree to do that - will I need to open the set to get the numbers of the boards before I order?


 


But before we close the case -


 


A) is there some testing I can do to narrow the selection to a specific board? Voltage test points, etc.


 


B) I noted in a posting on your by ricke1973 about a similar problems - and that service tech supplied a layout diagram as to the board placement within the case and an assembly diagram showing how to disassemble the case - is one available for this model as well ? How would I know which board is which without a layout?


 


 

Expert:  Aric replied 1 year ago.
The Boards are labeled at the links I gave to you, and they are for the Model Number of your TV. They say right at the links "SC" "SU" "SD" respectively next to them so you don't need to get any numbers off of the boards in your set.

I prefer not to reference another Expert's answers, as we are not always right on all of the time and also use different methods to troubleshoot. The 6 or 7 blink code indicates a faulty SC boards which commonl;y takes out the SU and SD. I always recommend replacing all three boards, but if you just want to replace the SC and see what happens that is your call.

I do not have an exploded parts layout, but if you remove all of the screws on the back of the TV the rear panel will come right off and you can visually idenetify all of the boards by referencing the links I posts to the specific boards for your set.
If you need further assistance, simply reply back and do NOT rate the answer. Also keep in mind that a "bad" or "poor" rating does not initiate a refund. You are rating the service I am providing you, not the problem with the equipment, or the fact that it may require service, or additional parts to fix the problem. The rating system is only to be used once we have successfully come to a conclusion, or a solution.

If this answers your question, please rate the answer with a "GOOD" or better, as it is the only way we Experts get paid for our work, and knowledge on the site. Bonuses are welcome and appreciated!


Aric, Technician
Category: TV
Satisfied Customers: 33118
Experience: 10+ yrs. experience installing and repairing TVs and A/V systems. Owner of A/V installation and repair business.
Aric and 5 other TV Specialists are ready to help you
Customer: replied 1 year ago.

Actually I was hoping that you could supply the same type of diagrams since you would have access the the service manuals and I do not. I was not asking you to compare your judgement to the other persons.

 

The reason for the service page request is to see the voltage check points or other techniques to figure this is the issue BEFORE I order replacement boards which are non-returnable.

 

Thanks, XXXXX XXXXX

 

 

 

 

 

 

Expert:  Aric replied 1 year ago.

I'm sorry, but I need to leave for the night, and will Opt Out and perhaps another Expert can assist you. Do NOT rate the answer, as your question is now open for other Experts to view, and if any can assist you with your problem, they will reply back to this conversation. Best regards, Aric

Customer: replied 1 year ago.

Sorry - didn't know we had a time line - anyway you did a great job and did in fact close the case with a good-service rating. Thanks

Customer: replied 1 year ago.

If you could find the board layout diagram and any board testing procedure / etc. I would appreciate it. Thanks

Expert:  TV Tech1 replied 1 year ago.

Not much in the way of testing the board(s). You can check DC voltages are present, but once you get to the SC's output and SU/SD inputs you really need to look at the waveform on a scope.

 

Here's some block diagrams, that's where you should start --

 

graphic

 

Let me know if you need or want the full blown diagrams. You need electronic skills to use those though.

 

graphic

 

 

 

 

Customer: replied 1 year ago.

Thanks, XXXXX XXXXX review this BUT what I was asking for is a "lay out diagram/schematic" that shows the placement of the boards when the back is removed. Usually just a line diagram. So for example the SU board would be shown as a small rectangle located (say right side near middle) within a larger rectangle (outline of the entire tv frame) and the SD board might be placed just to the right of this (as example).

 

Sort of an 'assembly drawing'.

 

Its for quick reference to the board names and placement on the chassis.

 

Thanks

 

 

 

Expert:  TV Tech1 replied 1 year ago.

I believe this is what you requested from Aric. I'm surprised he didn't deliver the "board placement" guide

 

Is this satisfactory, and what you need from me?

 

graphic

Customer: replied 1 year ago.

Perfect !!

 

Thank you for your attention and completion of this event.

 

As for Aric - I believe that he just ran out of time and had to leave - he did a great job of diagnosis and was clear in all details and communications. I was more than satisfied with his effort but wanted that last picture so when I took the back off the TV (before the parts arrived) I would know what I was looking at. (I hope he didn't think I was going to stiff him.)

 

I already closed this out - is there more for me to do?

 

Thanks again.

 

 

Expert:  TV Tech1 replied 1 year ago.
Actually there's nothing more for you to do. Aric didn't have the manual, but since I did, I just wanted you to get all the information you needed.
Customer: replied 1 year ago.

Oops -


 


I thought we were done here - installed the 3 boards as directed and TV powers up correctly HOWEVER, there are black bands running across the picture - some wide and others narrow. I am guessing that either (1) the copper colored cables are not seated correctly? OR (2) one of the boards is bad.


 


I want to get a stab at the fix before I have to take that heavy beast down off the wall again.


 


Thanks,


 

Expert:  TV Tech1 replied 1 year ago.

If those black bands are Left to right (horizontal) you will want to remove the TV and reseat/realign the ribbon cables that align up with the sections of black you are seeing on the TV screen.

 

If they are Top to bottom, it's the ribbon cables at the bottom of the TV set causing those. Same situation, the black bands align up with the ribbon cables directly in line with the band.

 

Anytime I have to reconnect those ribbon cables, I'll reseat them first, then power up the TV set with the rear cover removed. I recommend using the TV stand to keep it upright, and maybe activate the menu on the screen to find the black bands and see which ribbon connections are aligned to it. Once you get a normal picture, that's when you put the back cover on and remount it to the wall.

 

 

Customer: replied 1 year ago.

Your suggestion of using the base to hold the TV upright is a great one - will approach the issue as you have recommended. Thanks

 

PS - That was it - just in time for supper bowl with a working TV - Case Closed!

 

 

PPS - Oh no - watching TV via DirectTV into HTMI #1 - after about an hour of viewing - with back still off - TV went back and powered off - powered on again with the remote and got the same blinking light as the original question - 6 blinks followed by 7 blinks repeat 7 on an on. Unplugged TV. Let set cool for about 20 minutes and connected via a industrial extension cord to another outlet and powered up - same code 6 followed by a string of repeating 7s.

 

Now what???

 

 

Expert:  TV Tech1 replied 1 year ago.

Well....it's unusual but....

 

Since the problem seems to occur about an hour after running fine, we know the 6 or 7 blink code doesn't seem to be an issue with the high power/high current/high temperature boards you just replaced.

 

I got a couple pictures here to help you understand what that 6/7 blink code is supposed to tell us --

 

graphic

 

You would think those 3 boards are the source of the problem. They fail a LOT.

But once in a while, they could be operating fine, but the monitoring signal could actually be the source of the problem and since it fails when warm, we may want to try heating up the other two boards when they are cold and see if we get the TV to shut down and display the blinking fail code when they are cool.

 

This picture shows the entire fail code path. There's a D board and a DG board, and I suspect the D board FIRST. It shuts down the TV set. I think the DG board just recieves the signal from the D board, and makes the lamp blink on the front. I don't know 100% if it is the Master control computer or if the D Board's computer is the Master in this situation.

 

graphic

 

But if you warm up the D board....and the TV shuts off, then I'd say the problem is on the D Board.

But I'd also want to let that cool down, turn the TV back on....and then heat the DG board with a hairdryer.

 

We know it's heat related....so a nice icy cold, room temperature TV set will react when heat is applied to the faulty board.

 

Some will react almost instantly, others take 5-10 minutes. But you can't heat up one board, then heat up the other. You heat ONE up.....does or doesn't fail. Turn the TV off. Let it cool for an hour. Turn it back on, then heat up the OTHER board. No failure?

That's when I try the power supply board, because that SUPPLIES power to ALL boards !

 

Geez, sure hope you have a female in your home. I hear a hair dryer running in my house from time to time, but I have no idea where it exists.

You may be in the same boat as I am about hair dryers.

But, I usually set it for medium or high and wash the entire board with hot air while it's running. Don't put it right over an IC about an inch away.....that can hurt parts. But 4 -6 inches, moving it around....that'll heat up a board pretty quick. Try the D board first for about 10-15 minutes, then shut the heat off....let it absorb the heat and watch it another 15 minute. Does it fail?

 

If so, shut it off, try that SAME procedure on the DG board.....same time cycle. See if it reacts.

 

Which ever one causes a reaction.....COOL down the TV for an hour, and then REPEAT the HEAT a second time to VERIFY it reacts the same way.

 

Note this.....heat failures usually occur at a VERY specific temperature. Your hair dryer may very well heat it up so fast that the temperature shoots right past the fail point. That's why you heat it up, then take the heat off and watch it.

That's also why you run the heat test only on one board at a time.

 

Here's the locations of the boards in question --

 

graphic

Customer: replied 1 year ago.

OK I see what you are suggesting - Two Things:

 

I think you have it, but let me be clear - in the original problem and in the current state -- the TV never lights up the screen - the problem sequence is - plug in to power outlet - depress power on button - red led light comes on - 2 second later the red led shows the code of 6 then the repeating code of 7 - screen is dark the entire time. I seemingly can not use the power button to off the TV - only disconnect from outlet will kill the red led.

 

1) I wonder about the early failure of one of the three boards I just installed as this was something that just changed - so - is there a way to test voltage (or something else) or swap with the original boards to eliminate the early board failure possibility first? To be candid the SU board looked a little rough (dents and scratches, etc. - I know that in electronics that is not always a sign of problems).

 

2) I WILL carry out your suggestions with the hair dryer if you think that best before trying anything with the replacement boards.

 

Thanks,

Expert:  TV Tech1 replied 1 year ago.

I would heat up the boards with the good NEW boards installed. They work and can be trusted.

 

If I were to try swapping boards....I'd try only the SC board at most. Never swap the SU/SD boards back and forth, and never plug ONE in without the other one.

 

In both situations.....I've seen the smoke leave one of those postage stamp-sized ICs. Then both boards are damaged. Better safe than sorry.

 

Your old SU/SD boards.....look at the TOP of the postage stamp ICs on those boards. When they short, SOMETIMES they blow little pin-holes in the top of the ICs. I look for anything that looks like a hole, and then take a pin and see if I can actually find a hole or not. If it looks like a hole, a pin verifies it or tells you it's not.

 

Then of course there's the short test. With the boards unplugged, you can use your multimeter's continuity beeper and find the MAIN power foils/pins on the sockets and measure them to the Data pins usually found in the middle of the sockets. I find the MAIN power pins on the outside pins on the socket, data in the middle of the socket.

Stick one probe on the power.....stroke the data pins with the other probe and listen for a beeeep sound. That's shorted.

 

And you do have a GOOD working set of SU/SD boards to compare it to.

 

 

Customer: replied 1 year ago.

1) Not directly related - I noticed when swapping the boards the mfg used Locktite on the threads - should I do the same when re-installing?


 


2) I can hear the relays click - when plugged into the 110v, again when the power on button is pressed and again when the error code comes on. Sort of an old-school thing but is it possible the relays are sticking?


 


3) Is there anyway to reset the error code manually or is it dynamically done each time the set is powered up?


 


4) I read somewhere that this type of error was related to the HDMI input - is that possible here?


 


5) I see that your approach is to figure the error code generation maybe at fault - but what would/cause the SU board to fail? Over voltage, spike in signal, etc.?


 


6) Now onto the main event - I did heat up the board one at a time. Following this process - unplug TV - apply heat - touching the board to see how hot it is - plug in TV - power on button - check error code - unplug TV


 


OR did you what the TV powered up all the time and watch if the code flips? or does it matter?


 


The DG board is very hard to heat - can only see top 1/4 and there is that metal cage around it making it hard - did my best.


 


BTW - how hot is hot? Just short of melting the solder? burn my finger tip? I did something just short of burning my finger tip.


 


BTW - I noted that on the P board there are two neon(?) lamps at the center bottom - never have seen these lit up even when the set was working after the new boards were installed.


 


Summary - found no change in error codes while doing the "Hair Dryer Heat Up" - 6 one time then repeats 7.


 


-----------


 


While waiting to hear back I will try one more time to trip the boards


 


Lastly, I want you to know I think you are doing a great job trying to establish a diagnosis by remote control.


 


Thanks,


 

Expert:  TV Tech1 replied 1 year ago.

1) Not directly related - I noticed when swapping the boards the mfg used Locktite on the threads - should I do the same when re-installing? No, that's mostly for shipping purposes to keep the screws from unscrewing during all that travel time.

 

2) I can hear the relays click - when plugged into the 110v, again when the power on button is pressed and again when the error code comes on. Sort of an old-school thing but is it possible the relays are sticking? That's normal to hear all that clicking. Applies power to the higher voltage sections of the power supply board.


3) Is there anyway to reset the error code manually or is it dynamically done each time the set is powered up? Done automatically.


4) I read somewhere that this type of error was related to the HDMI input - is that possible here? HDMI isn't monitored, only the boards that use high voltage /high current are tested 90% of the time. There's a few minor system checks like data bus too.

 

5) I see that your approach is to figure the error code generation maybe at fault - but what would/cause the SU board to fail? Over voltage, spike in signal, etc.?

I'm kind of out of the Loop on that.... I went over Aric's responses and didn't see any info on that. Plus I noticed you paid him already.

 

I may have to forward you to the moderator Monday to get them to put your money back into your account from his account.

 


 


6) Now onto the main event - I did heat up the board one at a time. Following this process - unplug TV - apply heat - touching the board to see how hot it is - plug in TV - power on button - check error code - unplug TV


 


OR did you what the TV powered up all the time and watch if the code flips? or does it matter?Well, you could have left the TV on and got it warm to the touch, and monitored it's behavior, but HOT to the touch....it would have cooled down and met up with the board's normal warmup level eventually.

Heating it is just trying to speed up the process so you can see if you can control the behavior of the failure.

It almost sounds like heating it didn't change a thing at all. Do you agree or disagree? I wasn't there to see if there were any changes, like the TV shutting down faster or not.


 


The DG board is very hard to heat - can only see top 1/4 and there is that metal cage around it making it hard - did my best. That's ok, if you can't get to it, you just wash the general area with heat and it should respond faster I believe.


 


BTW - how hot is hot? Just short of melting the solder? burn my finger tip? I did something just short of burning my finger tip. Don't melt solder, and burning your finger tip is really too hot too. Warm it toasty warm. Imagine it's toast coming out the toaster. WARM but not painfully warm.

 

Fill me in on this SU board failing, I've went over the responses just to make sure I didn't miss anything, but I don't see any info about that.

I will tell you this....don't use it, and I do NOT suggest using the SD board coupled to it during the time it failed.

 

 


 


BTW - I noted that on the P board there are two neon(?) lamps at the center bottom - never have seen these lit up even when the set was working after the new boards were installed.


 


Summary - found no change in error codes while doing the "Hair Dryer Heat Up" - 6 one time then repeats 7.

Customer: replied 1 year ago.

OK - a review as requested AND and some new news AND payment issue

 

REVIEW -

 

TV is 50 inch Panasonic Plasma - Model TH50PE700U - built and purchase in 2007. I was watching TV for a three to five hour stretch (longer than usual for me) with a HDMI wireless Sony box (to get NetFlix, etc.) plugged into HDMI 2 (DirectTV box is in HDMI 1) . Next day turned on TV and no picture appeared but the power LED was blinking - code 6 then repeating code 7, code 7, code 7, etc. Could not turn off the power by using the push button - had to unplug from outlet.

 

Found your web site on the net and submitted question. Ordered and replaced the SU, SD, SC boards as directed. TV immediately had a picture with horizontal bars - re-seated the ribbon cables to the SC and SD boards and picture was perfect.

 

Watched TV for about 45 minutes with the back removed (HDMI 1 with the DirecTV box) and the screen just went black, the power seemed to cycle and then the power LED began to flash the same code sequence: 6, 7, 7, 7, etc.

 

You suggested to wash the boards with a hair dryer one at a time. Process was to heat a board, then plug TV into outlet, power up. EACH TIME THE CODE SEQUENCE DID NOT CHANGE - that is after heating each board and powering up each time the same code sequence 6, 7,7, etc repeated. Tests were done with nothing in HDMI ports.

 

-------------

 

NEW NEWS

 

I did some research on the internet and found several of interest on youtube.com - in particular this one - http://www.youtube.com/watch?v=yeGEH2FgMiM - which suggested a test to alter the bilink code. Consisted of disconnecting the SC board connections at SC2 (power input?) SC23 (interconnect of some type) and SC20 (interconnect of some type) . When I did that on my unit - the red led stayed lit with no blink code. Then I plugged in the HDMI 1 (DirecTV box) as input and - the sound came on - but no picture.

 

In addition the fans are turning so it is getting 15 volts from power supply.

 

Does this assist you in some way? If the SC board has failed again - what caused it?

 

---------------------------

 

As for the payment - how you do the internal thing is your call, but I am more than willing to pay for your time and effort and will arrange to pay you when we figure this out. I am not going to stiff you, but we should continue to attempt to come to a working conclusion. Thanks,

 

 

Expert:  TV Tech1 replied 1 year ago.

I have a button on my Just Answer page so that when I give the answer, it allows you to rate me or accept the answer. If you do that...that activates the payment. Don't worry about that part right now. I only press that when I think we've reached that point in the road.

 

The temperature sensor concept is a good idea, and yes it could have an effect if it were bad, but I believe when it goes bad it has more of an effect like this --

 

graphic

 

The thermal sensor is on the D board, as is the 6 and 7 blink micro. I think that's the board to consider replacing

Customer: replied 1 year ago.

The type of picture submitted has never been seen on my TV. Thank goodness. :0)


 


NEW NEWS


 


I did some research on the internet and found several of interest on youtube.com - in particular this one - http://www.youtube.com/watch?v=yeGEH2FgMiM - which suggested a test to alter the bilink code by disconnecting the SC board connections at SC2 (power input?) SC23 (interconnect of some type) and SC20 (interconnect of some type) . When I did that on my unit - the red led stayed lit with no blink code. Then I plugged in the HDMI 1 (DirecTV box) as input and - the sound came on - but no picture. In addition the fans are turning so it is getting 15 volts from power supply.


 


Does this assist you in some way? If the SC board has failed again - what caused it?


 


 


 

Expert:  TV Tech1 replied 1 year ago.

That video is for a dead set, 6 or 7 blinks. Your TV runs fine for a long time without failing. Am I correct that it still runs for about an hour....THEN it shuts off and blinks??

 

 

Customer: replied 1 year ago.

Mine is dead NOW - it does not run at all - at power up it generated the blink 6 one time and then continues with repeating 7s.

 

After replacing the SU, SD and SU boards it ran ONCE for 45 minutes then it went black and can not be restarted. So I would call it a dead duck. When trying to power up the code 6 followed by repeating 7 occur and the TV is not operational at all.

 

Then I tried the hair dryer on each board as you requested. One board at a time and found the same blink code 6 followed by the repeating 7s in each case. Same dead duck.

 

Then I saw the vidio and saw it as a way to test the code sequence. I disconnected the SU board from the circuit and it will power up and run AUDIO ONLY without issues. I have not left it running beyond 5 minutes. I am not sure if there is high voltage being produced, but the fans and audio are working.

 

 

Expert:  TV Tech1 replied 1 year ago.

I don't like the fact it only ran 45 minutes, then killed the SU/SD boards. When that happens it's the Plasma panel hurting/killing the SU/SD board. When you disconnected the SD board you also disconnected the SU board too. They share that common connection between the two.

 

If you try replacing the SU/SD again, it's going to take out those two boards again.

 

The only way to fix an intermittent short on the plasma panel is to replace the plasma panel.

 

 

Customer: replied 1 year ago.

I examined the entire screen, front and back for cracks, chips, funny looking pixels with a very bright hand held light . I could find no evidence of an physical damage. I know this may be the problem, but it has come back to life once with these exact symptoms.


 


Going back through the history generated some questions:


 


With the new boards in and after 45 minutes of running with picture and audio - the TV went black and generated the 6, 7,7,7,7,etc code - how do we know the replacement SC, SU, SD boards were not defective or weak and had an early failure? Have we jumped to a conclusion that replacing them again would lead to the same failure after a 45 minute run? What causes them to fail and need replacing?


 


If heat were the issue. Where / What would I be looking for during the 45 minutes of run time?.



I do not think that the one-time thermal fuse is the problem - Originally the set was working - then the problem - then replaced boards - and worked again immediately - if the one-time fuse had opened then it would still be open and the replacing of the boards would not have affected that unless the fuse is on one of the boards that were replaced.



Could it be a high voltage (or something similar) that punches the SC, SD, SU? if they have in fact failed. Is there any why to know which component failed?



 


If I elect to replace the boards yet again - what would we be looking for in term of trouble shooting?



Expert:  TV Tech1 replied 1 year ago.

how do we know the replacement SC, SU, SD boards were not defective or weak and had an early failure

 

We don't know....that's part of the problem. Do we Assume the boards are bad and order another pair? What happened to the original ones? Do you still have them?

This is your original symptom you stated --

 

It will not power up to display a picture. Instead it powers on, then the light blinks 6 time then repeats with a series of 7 blinks followed by a delay then again 7 blinks

 

Then you replaced the boards Aric recommended, I stepped in and gave you the details you needed, walked you through the Black band problem, and the new boards lasted 45 minutes and ---

 

after about an hour of viewing - with back still off - TV went back and powered off - powered on again with the remote and got the same blinking light as the original question - 6 blinks followed by 7 blinks repeat 7 on an on.

 

I'm extra leary due to that. Those boards are being stressed by its load, and that load is the plasma panel.

 

 

 

Customer: replied 1 year ago.

OK - one last go round - I have found this tech training manual and it helped me to formulate the ideas


 


1. I did as they suggested - used a strong light to examine the plasma screen panel. Did it 3 times - once shining down, once shining up and once straight into the panel - I could see nothing that suggested a problem existed. I know this may not be 100 percent but it looked good to me.


 


2. I disconnected the SC board from the circuit by removing the power connection at SC2, and the communication connections at SC20 & SC23. Audio came up and the SS board showed to have high voltage and the fans were spinning.


 


Then I re-connected the connections in various combinations - and with SC2 & SC23 CONNECTED the audio come up and everything works except the video. When the SC23 connector is inserted the power shuts down and the 6, 7, 7,7,7 code appears.


 


DOES This suggest another component besides the SC board failing?


 


In the attached document slides 39,40, 41 indicates that


 


SOS Code 6 --



  • An increase or reduction of the Energy Recovery Circuit output (MID). Open connection between connector A20 on the A board and SC20 on the SC board.

  • Open connection between any of the ribbon cables on the C boards and the A board.

  • Open connection between the ribbon cable/cables interconnecting the C boards.

  • Wrong diagnostic by the A board.


 


SOS Code 7 --



  • Missing Vsus.

  • Abnormality of the scan circuit output, the 5V_F, the scn_pro, and Vscn circuit.

  • Loose or open Connection between the SC board and the SM board (SC41, SC42, SC46).

  • Open or loose connection between connectors SC2/P2 or

  • Wrong diagnostic by the A board or

  • Defective panel SC SM Panel A


 


Does any of this suggest the A board or power supply or a runaway 5 or 15 or high voltage signal?


 


What / how could I test this theory?


 


Thanks,


 


PS ShopJimmy will test the boards for defects and report the components that failed to me - so I will do that


 


PSS this is my last attempt before I give in and lay out 20 cnotes for a new TV


 


PSSS - I cant attach the document as I expected - can you tell me how to send it to you?


 


 


 


 

Expert:  TV Tech1 replied 1 year ago.

Then I re-connected the connections in various combinations - and with SC2 & SC23 CONNECTED the audio come up and everything works except the video. When the SC23 connector is inserted the power shuts down and the 6, 7, 7,7,7 code appears.


 


DOES This suggest another component besides the SC board failing?

 

That part of your statement is confusing me Note that I expected you to state SC 20 made it shut down, not SC23 worked and SC23 did NOT WORK.

 

Did you mislable that part of the test?

 

1] We know the power supply board is ok, that's SC2

2] We know the SC board, along with the SU/SD and the plasma panel TOGETHER are shutting down the TV set.

3] SC20 Sends the control signals TO and FROM the SC board. That's why it stays on with SC2 and SC23 connected. When SC20 riibbon cable is connected, that's when the TV will shut down. It's because the D board gets a 5 Volt fail code from the SC board. At 0 volts it's going to sit there and be fine all day long.

Which does tell me that the SU/SD/SC boards all check out OK as long as you don't apply a signal to it.

 

So as long as the SU/SD/SC and PANEL don't get a signal....it works just fine.

 

Does any of this suggest the A board or power supply or a runaway 5 or 15 or high voltage signal?

No....those are connected -- their fail codes are still being monitored.

 

I still think the SU/SD or SC boards are getting hurt by the plasma panel. Those worked fine for 45 minutes without a problem, THEN they failed and NOW CONSISTENTLY generate the 7 Blink code again.

 

If my assumption is correct, what I just stated is correct....there's no way a bad board would be ok for 45 minutes, Then go bad and stay bad.

 

That document -- if it's a picture, you use the paperclip/Tree button at the top of your response box.

 

If it's a PDF file (most Triage and Training manuals are) you have to place it on a Free Download Website then post the URL here like this one --

 

http://tsn.pstc.panasonic.com/PASS/olt/files/Plasma/10th_Gen_PDP_TG.pdf

 

 

 

 

 

TH50PE700U

GP10DHU

 

Your unit is the 10th Generation --

 

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And SC 20 disconnected will let the TV stay on all day long --

 

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And I wouldn't mind looking over your Training manual. I got the first one, but I suspect they had a FALL training seminar. I went to the Spring one.

 

 

 

 

Customer: replied 1 year ago.

Well it's me again. All this time I have been waiting for replacement boards - everyone was out of stock - they arrived on Thursday night. So after dinner I got to work and plugged them into the chassis. I left the case back off of the unit so I could see if the LED were lit and hoping there would be more air flow.


 


The TV came to life - I ran it for 3 hours that night and then 4 hours the next morning and every thing worked fine. The green LED on the SC board was aglow all the while.


 


Then I let it play for 8 hours - still fine - and yesterday I left it on for 14 hours - when it went poof as before. The error code now is a solid 7 (before it started with a 6 for one cycle then followed by repeating 7's)


 


My conclusion are


 


 


(1) the original set of replacement boards had some weak or bad component which resulted in an early failure.



(2) Further that there is something that is heating up to the failure point after 12 hours - having the TV on for 12 hours was when the TV blew out the first time (original incident).


 


(3) the component that failed is on one of the three boards (SC, SU, SD)


 


(4) perhaps the set of boards are just marginally designed so that prolonged operations causes the component(s) to fail


 


(5) there are so many heat sinks - and long term heat build up may be a factor and one of the components under heat sink protection may be at fault.


 


So as my final question -


 


 


(1) from the notes about this chassis did the factory issue some new board / substitute board / that might have addressed this issue?


 


ShopJimmy has some corresponding boards with revisions which I have listed below with the original info (SJ) (See end of note)


 


 


(2) from your schematics and contact with the factory, etc. On these three boards (SU, SD and SC) what component is likely to fail?


 


What might that component be? Then I could test the board components to find it - after all I have three sets of boards to test.


 


 


 


 


Original boards and part numbers are:


 


SC Board - TNPA3992 (no revision no) Revisions available SJ - TNPA3992AC


 


SU Board - TNPA3990 (no revision no) - SJ has no other revisions


 


SD Board - TNPA3991 (no revision no) - SJ has no other revisions


 


 

Expert:  TV Tech1 replied 1 year ago.

Replace the SC board. You probably did get one with a weak part.

I doubt very much your plasma panel is going to "fail" right at 12 hours...if there was a problem the heat would have expanded it enough at 1 hour to make it go poof.

 

You just got a board with a weak part. Send it back to the company you purchased it from and get a replacement. Call them, and let them know it died on you after it ran for 30 hours total.

Customer: replied 1 year ago.

From your materials, can you figure the component that is failing?



Board is TNPA 3992 / SC Board / Panasonic TH-50PE700U / 50 inch plasma.



Could be a Diode but more likely a power transistor since these generate a lot of heat and that appears to be the cause of the failure. My thinking is that when the component fails, then the circuit shuts off the power to the SC board via the circuit you identified in an early reply and sets the error code to 7.



Is there a parts list available for the SC board?



Thanks


 

Expert:  TV Tech1 replied 1 year ago.

Let me see.....

TH50PE700U aka TH50PZ700U

GP10DHU chassis.

 

I'm never a BIG FAN of of merging two pictures together AFTER resizing them. Makes the text all blurry. Plus the picture is Ginormous too.

 

This should work, gives you the part numbers on the transistors and diodes, plus their locations, and finer details of the parts -- On the bottom of this picture.

 

The part numbers you should be able to Google them.

 

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Customer: replied 1 year ago.

Any thoughts on which might fail first? Diode are easy to test but the semi-conductor devices likely will need to be removed from the board for testing so zeroing in on an area would be best. (is there another way that doesn't require removal?)


 


You are correct the image was ginormous but not as big as I expected - nor was it fuzzy.



Thanks

Expert:  TV Tech1 replied 1 year ago.

Yeah, I decided to enlarge it, and get down to the nitty gritty of your situation.

 

I just ran 3 part numbers on several websites, and none came up with a PDF datasheet. Example --

 

http://www.alldatasheet.com/view.jsp?Searchword=2PG0010000RP

 

http://www.mouser.com/Search/Refine.aspx?Keyword=2pg0010000rp

 

It pretty much points to the fact the module has to be replaced. Did you contact your part supplier to get an exchange?

 

Let's deal with the original part number and the Allowable Substitute here --

 

http://www.encompassparts.com/item/7350652/Panasonic/TXNSC1ETTJ/Pc_Board

 

TXNSC1ETTJ Original

 

TXNSC1XCTU Sub

 

http://www.encompassparts.com/item/7569285/Panasonic/TXNSC1XCTU/Pc_Board

 

 

TXNSC1HHTUJ Sub #2. Looks like they made some modifications.

 

http://www.rivervalleyelectronics.net/p-3029-panasonic-txnsc1ettj-y-sus-ysus-sc.aspx

Ok, TNPA3992 on the board is the original board.

 

I just wanted to make sure we had original, before we proceeded.

 

Overall, you can order TNPA3992 or TXNSC1ETTJ

 

TXNSC1XCTU or TXNSC1HHTUJ can be used too.

 

 

 

Customer: replied 1 year ago.

I gave the board a good visual inspection with a magnifying glass and found nothing to point out a failed component.


 


Any thoughts on which might be the most productive place to start looking for the failed component?


 


Thanks for the parts listings. They will allow me to begin the search for suitable replacements - I know they are not likely to be available but there should be some substitutes available.


 


I don't feel too good about just inserting another SC board however. Seem a crap shoot if first replacement lasted 45 minutes and second replacement lasted 12 hours - who knows how long this one will hold on. And this is the driving force to figure which component failed so to make sure I find the root cause - right now I am just guessing heat is the problem - could be (1) over-current is the real cause and heat is only the symptom or (2) the heat is building up during the 12 hours because the heat sink is not appropriate, or component doesn't have one, and the temp goes above the failure point.


 


I did get ShopJimmy to replace the board (you called it a module?) so early next week I should be ready to go again. Ordered the same part number as the original.


 

Expert:  TV Tech1 replied 1 year ago.

Seem a crap shoot if first replacement lasted 45 minutes and second replacement lasted 12 hours

 

To be honest, that's NEVER good. 2 boards failing? If I was buying cheap boards from an Ebayer....Then I'd say I'm just getting bad boards. If I was getting them from ShopJimmy or maybe Encompass...then I'd say I'm getting good boards but the TV set is eating them.

 

Then it comes down to is the SU or SD boards defective or is the Plasma panel defective?

 

And when it comes down to it....the SU or SD boards would have smoked one of its ICs by now. So overall, it has to be the plasma panel is eating them. I kind of have a rule created from my experiences with your situation.

 

If it eats one board...it's a bad board. If it eats two boards...it's a bad plasma panel.

I can add details, like the SU SD boards will smoke their ICs when you install any FIRST new board. That's been my experience too. But I've rarely seen a bad SU/SD board that let a TV run 45 minutes to 12 hours displaying a good picture.

 

Now that I know this information, two boards went bad already...I think we are dealing with a bad plasma panel. I was thinking you had only replace ONE board and it lived for 12 hours no problem at all.

 

 

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