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bluextc89, Technician
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I have a Hitachi P50S601 TV and it wont power on at all.

Resolved Question:

I have a Hitachi P50S601 TV and it won't power on at all. I purchased a power supply board HA02202 online and it still doesn't come on, no fans or anything. Just some humming out of the power supply board. I called the company that sent it to me and they said it came out of a working TV. The only other board that could be causing the problem is the small board that the power cord plugs into that have the ON/OFF switch attached to it but that board is putting out 120vac.
Submitted: 5 years ago.
Category: TV
Expert:  bluextc89 replied 5 years ago.
Thanks for stopping by.

Initially, unplug the power cables going from the Power Supply to all other boards...

Attempt to power on - and let me know if the result is the same, or anything changes.

Customer: replied 5 years ago.
when all the other boards are unlugged I get nothing, not even the buzzing I heard before.
Expert:  bluextc89 replied 5 years ago.
What type of voltages are you getting for the Vs Va 5V etc? With everything except the smaller P/S board (aka Filter PWB) unplugged?
Customer: replied 5 years ago.
I don't know where to measure those.
Expert:  bluextc89 replied 5 years ago.
Well that may be an initial problem with troubleshooting your set.
When you replace a P/S - you have to make an adjustment for the Va Vs and 5V based on the sticker on the inside of the set. No 2 sets are alike... and the tolerance for the Va is +/- .2V and Vs is +/- .1V

Reply with your panel voltage information, and whether you have a multimeter in order to proceed. (Do you have any experience with plasma tv repair?)
Customer: replied 5 years ago.
I have a digital multimeter and I know how to use it. I have experience as an electronic tech so I could read the voltages if I knew where to read them (I don't have a schematic). I see a sticker that says

+5.1/+80-95/+50-70 V
4.5/4.9/3.0 A
Expert:  bluextc89 replied 5 years ago.
Ok - that's the correct sticker.

On the upper right side of your P/S - theres a CN99 cable connector.
Just to the left of it should be a 3 pin test point.


Put your ground probe on any chassis metal (advise vacant screw hole) and power the set on - give me the voltages you get at pin 1 and 2 of the test point.
Expert:  bluextc89 replied 5 years ago.
Oh - the sticker you're seeing is a broad voltage sticker. We need the panel voltage sticker.
It probably says LOT <N6> or something similar... then Vs Vw Va and Vx voltages listed
Expert:  bluextc89 replied 5 years ago.
Also - check the front panel, and see if there are any LED indicators - if they are solid, flashing, and what color they are.
Customer: replied 5 years ago.
Not getting any voltages on those pins. Tried different grounds. No luck.

Found the other sticker:
Vs= 88.9V Va= 65.4V
Expert:  bluextc89 replied 5 years ago.
unplug the set.
plug in all the boards you unplugged back to the P/S
there is likely a shutdown circuit at work.

then take the same readings at pins 1 and 2 after powering on.
Put your probe on pin #1 as you power it on and watch it for any fluctuations.
Power down the set - then do the same on pin #2

Let me know what you find.
Expert:  bluextc89 replied 5 years ago.
P.S. I didnt indicate it earlier - but if you don't have an auto-ranging meter - we're looking for DC voltage.
Customer: replied 5 years ago.
Yes, DC. Nothing on pin 1. Got 3.4 on pin 2.
Expert:  bluextc89 replied 5 years ago.
Ok - the power supply isn't making the Vs or Va voltage.
Let's check for 5V output...

On the CN63 connector - what is the voltage at pin #1?
Customer: replied 5 years ago.
5.3 with the connector connected. BTW thanks for hanging in there with me.
Expert:  bluextc89 replied 5 years ago.
ok - that's good.
we have to figure out why the Va and VS aren't being made.

Check the SBY+5V on connector CN63 pin 1 for that same 5.3V
Also check for 3.3V on pin 3

and let me know if there are any flashing or solid indicator lights on the front of the set and color.

Customer: replied 5 years ago.
Don't understand. I already checked the CN63 pin 1 with the connector attached and got 5.3V. I don't get anything on pin 3 on CN63 with the connector plugged in.
Expert:  bluextc89 replied 5 years ago.
Ok.... then you're missing the low standby voltage as well.

The next one can be a little tricky -

On that same CN63 connector - pin 6 is the PoWER1 High and should read 5.6V (eventually) - may take a few seconds to build up.
Also - pin 7 is the PoWER2 High and should read 10-12V (eventually)

Is this happening? Test both individually - and let me know what you find.
Customer: replied 5 years ago.
pin 6 - 4.8
pin 7 - 3.2
Customer: replied 5 years ago.
Do you think the power supply board is bad?
Expert:  bluextc89 replied 5 years ago.
Since neither of these are attaining full voltage - the Main-Digital PWB is suspect.

What was the original reason you replaced the P/S? Same no-power-on condition?

A few more things to check.

Do you have a CN68 connector on the P/S?

If yes - check pin 3 (Vpr2) for voltage - what do you find?
Expert:  bluextc89 replied 5 years ago.
Now remove the CN6 connector (PSU-Logic Board cable) and re-check the Vpr2 voltage.

Is it present?
Customer: replied 5 years ago.
No voltage on pin 3 of CN68 with or without connector plugged in.
Expert:  bluextc89 replied 5 years ago.
ok - that seals the deal then.

With no voltage on the Vpr2 (should be 3.3V) with the P/S-Logic power removed - it indicates an abnormality in the Standby Power Supply, and the P/S is defective.

Had there been Vpr2 voltage with the cable removed... but NOT when it was plugged back in - the Logic board MPU (Standby Power Supply) system whould have likely had a short circuit - and the Logic board then would have been the culprit.

From your readings - I am confident you have a defective P/S. Now whether it was SHIPPED defective - or another problem in your set CAUSED the defect... without further tests I can't say for certain.

For the sake of trying - plug everything in - except the power going to the XSus and Ysus boards... and power on. Does the "buzzing" stop?
Customer: replied 5 years ago.
No it doesn't stop when I unplug the XSus and YSus boards. Btw buzzing sounds like it's coming from the L002 coil.
Expert:  bluextc89 replied 5 years ago.
Source another P/S and when you get it - you can re-open this question, and I can continue with voltage setting.

I Suggest when the new board is installed - test it by itself (no peripherals plugged in) as we did above.

I am stepping out for a few hours. No need to reply until you get your new board.
If there is anything I feel I missed after I go through my reference material - I'll let you know. Right now - the PC I am at is not good for viewing much Laughing

bluextc89 and 2 other TV Specialists are ready to help you
Customer: replied 5 years ago.
Ok Thanks.

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