Panasonic TH-42PZ85E --> Completely dead!

[Moreno83]

Hey guys ,

Got a very nice th-42pz85e here for a cheap price! ( Tv looks brand new!! )
The guy who sold it said that the tv was playing fine and when he touched the power button to turn it off a electric shock was visible and the tv shut down. ( Static shock between fingers and the button ).

The tv was not opened before and when i plug in the power cable nothing happens , no led , no clicks , no fans , nothing!
The last Panasonic that i fixed has almost the same power supply.

Power supply : ETX2MM702MF

So where to start? I have not seen a Panasonic yet that does absolutely nothing! :o

1uf caps on MC201,MC301 ?

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Changed the TDK-Lambda EMC filter but nothing changes.
All caps look fine and the fuses are ok.

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

1uF caps would not cause dead no power.

P board is a possibility, check 5VSTBY from PSU.

Check button is seated properly, and connections to PSU are there. (The power button interrupts the 5V standby supply to the main board. The signal is routed through the SS board into the P board. It turns off a FET on the P board to cut 5VSTBY power.)

Can also be A board as I've found out - this would be if the 3.3VSTBY is dead and 5V is NOT...

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Could you tell me what to do exactly? I got a Fluke multimeter but i don't know where to measure

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Im going to check the power button first. I don't know how to measure the 5v SB/ 3.3v SB.

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Start with service manual. Check 5V using the diagrams.
Cathode of D551 on P board has the 5V standby on it (before switch on.)

Unplug connectors P6 & P7 on P board, and A3 & A5 on A board. If A board is causing dead no power TV should click on, screen will glow light grey then full white. Power button needs to be pressed in. Can confirm this works on a TH-42PZ8BA.

Find service manuals here: http://www.toms-service-manuals.com/

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Tom , as always thx for the help! Much appreciated…i keep learning more & more!!

I have not checked the power button yet , was removing some screws on the bottom and saw your post.
I removed P6/P7 + A3 & A5 and the rest is connected but the tv is still completely dead!

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

D551 = 5v

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Ok, check pin 29 of P25 / A25 connector for 5V standby. Restore original connections.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

There is no pin 29? P25 has 12 pins , all pins are 0v with just the power cable connected.

D551 = 5v at the same time.

The blue/white cable going from the power button to the SS board is 1.85v/0v/1.85 V

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Sorry, meant pin 9... doh.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Haha np!

Pin 9 is 0v.

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

OK, this means the power board is not turning on the 5V standby for some reason.

If you've got some freeze spray try spraying module MC501 (not 201/301) to see if it turns on. (Allow the spray liquid to evaporate first.) In particular focus on the small ceramic capacitors on it.

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Oh, and check if pressing the button changes those pin voltages..

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Don't have freeze spray right now , will buy a can this monday…..
Could you tell me what the values are? I got all range capacitors so replacing them won't be a problem and could save me a lot of time.

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

Problem is I don't know what the capacitor values are. I've fixed one before by replacing that module from a scrap board.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Ok np , the service manual does not mention the values either and if the caps are bad i still can't measure them right?

When i press the power button nothing changes ( Already checked that ). Power button works because the values change on the SS board.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

Those parts are not for sale right? Just searching for ETX2MM702MF on ebay and i find the power board and the MC201/MC301.

Is it wise to use a can of air and hold it upside down? Don't want it to corrode later ….

[tom66]

Re: Panasonic TH-42PZ85E --> Completely dead!

The liquid does not corrode but do allow it to dry first.
Yes the part is not available hence why I took it off a scrap board, I did trace it out if that helps but never determined the values of the capacitors.
https://www.badcaps.net/forum/attach...8&d=1367795705
(PNP Q3 drawn backwards by mistake...)

C2 or C5 are suspects.

[Moreno83]

Re: Panasonic TH-42PZ85E --> Completely dead!

I understand but i don't have a scrap board
The tv is really looking brand new , not even a scratch!! Bought it for 60 So i really want to fix the tv

I will desolder the part and measure some of the parts. Any tips?