Panasonic TH-42PZ85E --> Completely dead!

[Moreno83]

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

Anyone know the values of the caps on MC501 board?

[Moreno83]

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

I attached a picture of the powersupply and the MC501

[Moreno83]

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

I bought some freeze and used it on the mc501. Nothing...

[Moreno83]

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

Here a picture of the mc501 board wich is frozen. It was not possible to freeze just this part only....

[Moreno83]

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

Measured:

D551: 5v
D606: 0.25v
D702: 4.8/5v
D604/603: 0.15v
L501: 3v
D505: 0.2v
D506: 4.85v

D504: 0v?
Measuring D504 with diode testing says both sides peeping noise.

Replace d504?

[Moreno83]

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

Nobody?

[vinceroger69]

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

if possile remove the diode from the board and retest some times diodes test sc when on a board you remove them and test again there fine.

[Moreno83]

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

This diode is fine. I also replaced the 22uf cap but the machine is completely dead....
You dont think its SS board?

[tom66]

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

Why would it be SS board?

[Moreno83]

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

Well if 1 of the cables on SS board is not attached to the powersupply the machine wont do anything. ( my experience..i could be wrong).
So i thought that if ss board is bad...it wont send a signal to the powersupply? Because the powerbutton cable is also going to SS board.

[tom66]

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

It just acts as a way to route the signal - it doesn't do anything with that signal.
Reduces wiring clutter and harness costs.

[Moreno83]

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

Ok that explains it. Haha.
So any thoughts on this tv?

Could you check the voltages with your "dead" machine?
Pin 9 is still 0v, i used freeze on every part on the PS, the area around the 5v stb diode was the first to be defrossed.

[tom66]

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

Ok, what do you want me to check? List the connector and pin numbers and I'll get you the measurements.

[Alastair E]

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

I use standard 1uF 63V elccy-lytics for the MC boards.....

I believe the multi-layer ones go leaky depriving the chip of supply voltage causing the faults these caps are known for....

Haven't had any issues with those Ive done. They decouple the supply to the chip, so are not critical, anything from say, 0.1 to 10uF would do it .

[Moreno83]

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

A few posts above are the part numbers with the voltages.
I replaced capacitors D506/507/508. C551 and all small capacitors near p25. 470uf/100uf.

Machine shows no.sign of life..

[Moreno83]

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

Could it be that the mainboard is dead? Processor on mainboard is telling the powersupply to turn on right? ( to turn relais on ).

[tom66]

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

Could it be that the mainboard is dead? Processor on mainboard is telling the powersupply to turn on right? ( to turn relais on ).

No. The main board does not command the 5V standby to turn on (only AC-DET and main on/off switch do) ... if it did, how could it send the signal, with no power?

[Moreno83]

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

Ok , makes sense.
So its the power supply , i replaced almost ALL capacitors except the big 450v and 3 small caps next to the small prints.

Btw i also used a different on/off switch from a other panasonic , does not help.

[tom66]

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

You need to look at the schematic to see what controls the 5V standby, check if that device is getting a signal to turn on, rather than shot-gun replacing parts which doesn't help anything.

BTW, every time you take apart the power supply, you are screwing all the devices back down, and putting the plastic in right... otherwise you risk a very bad failure...

[Moreno83]

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

I understand , ill try and look at the schematic.

No , not all screws. Right now im just waiting for the relais to give a click. I understand what your saying and ofcourse i wont let the tv stay on without all the cooling placed correctly.

The problem is that it doesnt do ANYTHING at all. So i thought i would use the shotgun tactic and replace some caps , you never know.
The problem must be somewhere on the PB and im honest , i dont have the knowledge yet to get a schematic and just point out the problem

Thanks for the advices your giving me Tom , much appreciated but im not that good with tv's yet as you are!