Hi TechniWizard - thanks for your reply.

The situation has changed a little. I tried pulling the SU board, the SD board and both of them together, but every time I turn the TV on now, it sits for 2-3 seconds and then a red LED (marked D853) on the SC board lights up briefly and the TV turns off. Then I get the two red flashes again.

So - bad SC board? I'm wondering if I'd be better off just replacing all 3 of them...

I see some on ebay. If you happen to have any for sale, please send me a PM?

Thanks,

\ Henrik

Yes, the SC is a prime suspect, but the SU and/or SD could be bad also.
Some of the later series' 7 blink troubleshooting tips may work on your SC but if you have zero electronics experience, I would not recommend DIY.

TW

Dude, your case is like icecream, you must chase the heat factor.....

ALL ELECTRICAL MOSFET GET HOT AND STOP WORKING ONCE CAPACITANCE DROPS DOWN THE MINIMUM LIMIT TO CHARGE DC VOLTS THAT LATER ON WILL BE USED TO GENERATE THE HIGH VOLTAGE SIGNALS.

PLASMA TV USES UGE CAPACITANCE ........ ON MAIN POWER BOARD AND MEDIUM CAPACITORS AT THE SS AND SC BOARDS.

Please, follow this instructions.

1:=>Remove again your tv stuff in order to get access to all the boards you suspect has the problem.

2:=>Turn on tv and wait to it turn off by overheating and check if your fun were powered on during this overheat process, if fun does not turn on, this is the problem, check why your fun is not powering on, IT MAY BE A FUN BROKEN .... SENSOR FAULTY...... OR EVEN YOUR "D1" FAULTY.

3:=>After it turned off, remove all the power and wait some seconds in order to the capacitors to discharge.


4:=>Once the power cord is removed, check with your fingers the very hot parts.

IMMEDIATELY BEGIN TO PUT YOUR FINGERS ON ALL THE "POWER COMPONENTS CHASING HOT PARTS".

5:=>Chase the tracks untill you got the nearer capacitor of those parts that is hot.

6:=>Check for visible blown up capacitors, it will be abnormal fat and hot, components overheat in majority of cases because missing of capacitance on main power that supply those voltages.

8=>Replace the capacitors blown up.


GOOD LUCK

ALL ELECTRICAL EQUIPMENT STOP WORKING ONCE MINIMUM CAPACITANCE REQUEIRED DROPS DOWN ITS LIMIT.

THIS SHOULD BE THE TEACHERS LESSONS ON HARVARD UNIVERS. WHEN A CAPACITOR GETS HOT, DC CURRENT STOPS OR BECOME UNSTABLE.

IN THIS TV, IT HAS AN IC THAT MONITORS THE VOLTAGE AND TURN OFF TV ONCE VOLTAGE FALL DOWN ITS MINIMUM REQUIRED.


ALLLLLLLLLLLLLLLLLL THIS IS CAPACITANCE PROBLEM....... I DID REPAIRED HUNDREDS OF HI POWER EQUIPMENTS ONLY REPLACING KEY CAPACITORS.

GO EBAY, FIND A PRECISE CAPACITOR TESTER

I AM NOT SELLING NOTHING JUST TRYING TO EDUCATE PEOPLE INTO THEIR SOLUTIONS.....

HERE ON EBAY HAS A VERY GOOD CAPACITOR TESTER IN MY OPINION OF TECHNICIAN.

http://cgi.ebay.com/EC153-Capacitor-Capacitance-Tester-Meter-up-20000uF-/320382430754?pt=LH_DefaultDomain_0&hash=item4a9847ee22

GOOD LUCK.

TW, maybe you can diagnose the issue:

When I turn the TH-50PHD8UK unit on, four thin vertical lines appear on the left side, going from the bottom of the screen to halfway up the screen (2 red and 2 green, each is 1-pixel wide). I can toggle the inputs with the remote and I can see the input displayed in the upper right-hand corner. The lines on the left are there in every input. After a few seconds, the GREEN (not red) light blinks 5 times, each time with audible clicking, as if the unit was trying to turn itself on/off. During the clicking cycle the lines disappear, only to appear again after 5 clicks. And so it continues until I power off the unit.

I disconnected all the cables, removed all power for a day - same thing. Any idea what might be wrong? Thanks!

TW,

I am local. How much do you charge for your services for the Panasonic TH-42PA20 shut down issue FIX.

PLease let me know if you are interested in some business.

TW,

I am local. How much do you charge for your services for the Panasonic TH-42PA20 shut down issue FIX.

PLease let me know if you are interested in some business.

Look for a PM.

The unit must be June - August 2003 production to have this symptom.
And 2 or 5 blinks, counted as they go dark.
Usually takes 30 min - several hours to shutdowm.
Changing channels or high brightness causes more often.

Otherwise it is another problem.

I've got the 7 blink problem. It seems swapping out the IC unit in the power panel would be the fix.

Hello - I've read most of this thread, and others I can find on a search for Panasonic TH-42PA20.

( know this is slightly off-topic, but this seems the most alive thread on it!)

(might be a TH-42PA20E - I'm in New Zealand, a PAL country)

I recently picked one up from Freecycle.
It had just gone faulty;-they replaced it.

I have no power LED light, but (with no video/aerial input) I just get a flowing multicolour purplish static on the RH side of screen.

The SC & SS board LEDs are lit, but on close inspection this resistor R461 is so burnt (& is open circuit) that I can't read its value.

It's in the collector circuit of Q491 just below it. Q491 appears to have shorts, on a diode test.

This seems to be (I guess) a revison 3 board - the set is dated 2004 from memory (I just reattached the back, with this board out.)

The layout is slightly different in this area from the board layout in the service manual(s) from ElektroTanya.com.
Also different in this area from an SC (rev. 1?) board I saw for sale.
(Q491 on that was small, like Q492 in my pic)

It's frustrating that in all the material (6 items now, two per day!) that I've downloaded there, there's only a small "revised components" list and nothing overall; certainly not for this (or any other) SC board.

Can anybody please help with this resistor value? (see attached pic)

I may have to replace Q491 2SD1263A & Q492 2SC1473A as well.
From what I can gather from the block diagram, they and IC491 are parts of the VSET regulation system

There were some shreds of sooty dust about; - maybe a cause of the problem, or just component failure?

Very grateful if someone is familiar with this revison of SC board & can look up this value for me - or read it off an actual board!

Thanks & kind regards,

Ross_M

LED Chart for TH50PX25UP

7 Blinks is the SCAN area, where you found the 2 bad resistors.
Try to power up with the SU or SD disconnected from the SC board. Leave the ribbons to the panel connected.

Look for a good upper or lower 1/2 screen. The removed PCB is likely bad if the other 1/2 screen appears.

TW If replacing the resistors don't fix it what else should I look for.

My TH-42PWD6UY panel has seen very little use over the years and has finally started to shut down daily with 5 blinks. Unsure of the build date because it's wall mounted, but it's probably around June to Aug 03, because it was purchased in late Sept 03.

I'd like to know if there's a reasonably priced source for IC551 (C5HABZZ00123) other than Panasonic factory parts, since $35 delivered seems a little dear for a simple IC. I did find a source in Canada, but other than that, the part made by Sanken appears to be discontinued.

Thanks,
Byron

My TH-42PWD6UY panel has seen very little use over the years and has finally started to shut down daily with 5 blinks. Unsure of the build date because it's wall mounted, but it's probably around June to Aug 03, because it was purchased in late Sept 03.

I'd like to know if there's a reasonably priced source for IC551 (C5HABZZ00123) other than Panasonic factory parts, since $35 delivered seems a little dear for a simple IC. I did find a source in Canada, but other than that, the part made by Sanken appears to be discontinued.

Thanks,
Byron

I still have a dozen or so of these brand new in the box. I could do $25 delivered. Look for a PM.

T Wiz