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Anthony_Infotech
Anthony_Infotech, Technician
Category: TV
Satisfied Customers: 13727
Experience:  20+ years experience TV expert (field and bench) 9 approved qualifications in TV-ELECTRONICS
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Magnavox MS3252S431...turn tv on, no picture...only power

Customer Question

Magnavox MS3252S431...turn tv on, no picture...only power button is lit...have heard that it might be a fuse, or could be a C2455 [email protected]..how do I check these things...or any info other than this you might know...please
Submitted: 1 year ago.
Category: TV
Expert:  Anthony_Infotech replied 1 year ago.
Hello
Welcome
Thanks for the Question
You have tried switching the set on manually at the set itself just to eliminate that ?
Anthony
Customer: replied 1 year ago.
yes...tried turning set on manually...did not work...same result...
[fyi]...unplugged tv last night, and just a minute ago I pushed power button in and held for 60 seconds just to hopefully drain some power [like I do on computers before working on them...don't know if it helped, but sure it didn't hurt anything]...
anyway...?...
Expert:  Anthony_Infotech replied 1 year ago.
Yes you have done all you can the first thing to do is have a visual inspection of ALL the capacitors on the powerboard look for leaking/ballooning/raised domed tops can you do that first?
Anthony
Customer: replied 1 year ago.
yes...I guess to access this power supply board to inspect these capacitors, I just need to remove all screws on back of set?...and then cover will come off?...
Expert:  Anthony_Infotech replied 1 year ago.
Yes just get the back off the set and trace the power-cord to the power-board
Let me know, take your time no rush
Anthony
Customer: replied 1 year ago.
is there a good way to raise this monster up off table so as to access bottom screws easier and make it easier to work on?...
Expert:  Anthony_Infotech replied 1 year ago.
I honestly don't know there are so many models I can't remember you may need to take the set off any pedestal stand and lay it on a very soft blanket or mattress be very careful not to damage the panel (screen)
Anthony
Customer: replied 1 year ago.
this is like parking a Volkswagen on kitchen table to work on it...are you saying to lay tv face down on screen to remove back?
Expert:  Anthony_Infotech replied 1 year ago.
My apologies I thought we was working on a diff model
Expert:  Anthony_Infotech replied 1 year ago.
This is a CRT set
Expert:  Anthony_Infotech replied 1 year ago.
So same procedure applies but you do need to get the back off forget the other ideas because I thought it was an LCD set
Customer: replied 1 year ago.
so...is there a good way to raise this monster up off table so as to access bottom screws easier and make it easier to work on?...
Expert:  Anthony_Infotech replied 1 year ago.
You should be able to get at all the screws from the back of the set there should not be any screws underneath
Expert:  Anthony_Infotech replied 1 year ago.
Its then a matter of pulling the back off
Customer: replied 1 year ago.
there are a couple on lower backside of cover, and not much room to get to...guess will have to do best I can
Expert:  Anthony_Infotech replied 1 year ago.
I just cant help you with that and yes it a matter of working that out all sets are different in one way or another I cant recall having any issues with the back
Anthony
Customer: replied 1 year ago.
welp...got it open...doesn't look like a lot going on...
Expert:  Anthony_Infotech replied 1 year ago.
There is though
Most suspect is the regulator just behind the yellow switch mode transformer on the heat-sink there should also be one or two capacitors just behind that transformer in the gap between it and the regulator, one thing though you have to be very careful as the HT capacitors will be charged up if you decide to replace that regulator so leave the set off for some time before replacing it (or the caps).
I am doing this from memory the chassis was used in a lot of different manuf sets
Let me know if you need more info
A positive rating is appreciated thank you, ***** ***** be a rating bar of smileys or stars with this post please pick out a positive rating and click submit or finish thanks again, rating me positively is the only way I receive a proportion of the fee from the site.
Regards
Anthony
Customer: replied 1 year ago.
not sure which is the regulator...
Expert:  Anthony_Infotech replied 1 year ago.
As you look at the yellow transformer in the first pic at the back of it is the heat-sink with the regulator strapped to it
http://snag.gy/BY3Ne.jpg
Have a look at the graphic above
The X is the heatsink I have marked where it is
Anthony
Customer: replied 1 year ago.
I see the regulator strapped to heat sink...how do you test the regulator please?...
Expert:  Anthony_Infotech replied 1 year ago.
You can't check these devices you can only replace it as its basically a chip not a transistor
Anthony
Customer: replied 1 year ago.
so no guarantee that this regulator is the problem...what is this regulator called...plus I don't seem to see any ballooned, domed or leaking capacitors...don't know if you can from pictures or not...
Expert:  Anthony_Infotech replied 1 year ago.
No we have moved on from the caps they look OK there may be one in the gap that I cant see between regulator and transformer so take a pic of that, and no gaurantee with anything in servicing of electronic equipment even when checks are made however I have had this several times, when I am giving you advice here I am considering the safety aspect of the work so I don't want you taking voltages around there because its difficult to work on and dangerous there are very high voltages around that area, the regulator has its identity on its body
Anthony
Customer: replied 1 year ago.
I thought that the last image I posted shows between the regulator and transformer...doesn't it?...
Expert:  Anthony_Infotech replied 1 year ago.
Yes sorry it does I didn't see it!
OK that high voltage cap looks OK
Please be careful even with the set off that huge capacitor you can see in the last photo (has 0421 on top)needs to be discharged it probably is not charged because the set is in standby but it can get charged heavily even in standby ideally it needs to be discharged (set unplugged from wallpower)that can be done with an insulated wire holding with insulated pliers short across its terminals underneath the board
Get the code off the reg and let me know what it is please
Anthony
Customer: replied 1 year ago.
here's the image again...if this is not what you mean please explain and I will be glad to take another picture please
Expert:  Anthony_Infotech replied 1 year ago.
I am sorry I just indicated I found it?it looks ok
Anthony
Customer: replied 1 year ago.
sorry, replies crossed...can't seperate back enough to get close look at regulator...is there a trick to seeing the code?...there is some numbers on heat sink, don't know if that's code for regulator, but here is another picture...thought maybe numbers below lightening bolt might be regulator code...
Expert:  Anthony_Infotech replied 1 year ago.
Just take the clip off?the clip holding the regulator to the heatsink
That will let you see it
Anthony
Customer: replied 1 year ago.
oh...the clip is only thing holding regulator on...thought it might be soldered somewhere...
Expert:  Anthony_Infotech replied 1 year ago.
Yes its soldered to the board underneath but the clip is obscuring your view of the code as its on its body
Customer: replied 1 year ago.
removed clip, but don't see any letters or anything...where would this be on regulator please
Expert:  Anthony_Infotech replied 1 year ago.
In that case you will need to de-solder it out of the set, its ID WILL be on its body
Anthony
Customer: replied 1 year ago.
will it be necessary to disconnect all cables to board to get board out before de-soldering regulator
Expert:  Anthony_Infotech replied 1 year ago.
Not normally it can be manipulated into a position where you can get it out however if you need to unplug one of those leads please do it no need to de-solder anything out other than the regulator
Customer: replied 1 year ago.
been trying to remove back completely so can manipulate tray with board on it easier, seems to be one thing holding it to back cover [beneath/around] the audio/video jacks that I can't figure out how to release...any ideas please?
Expert:  Anthony_Infotech replied 1 year ago.
You should not have to do that?if you want you may be able to take that plastic off there may be screws on the AV inputs and elsewhere.
Anthony
Customer: replied 1 year ago.
well I'm assuming that the regulator is soldered to bottom of the circuit board, and with the board attached to this large cabinet back, I can't turn circuit board over to de-solder regulator because of the cable 'leads' you said didn't need to be disconnected...
Customer: replied 1 year ago.
when I flip circuit board over, I loose the regulator...how do I find regulator on soldered side of board?
Customer: replied 1 year ago.
well that kinda stinks...tv apart on kitchen table...and expert bows out and leaves me hanging...thanks