Panasonic TH-50PZ81B

[vaxthehunted]

Hi There,
I'm looking for a bit of assistance on a Panasonic TH-50PZ81B. It is the first plasma tv ive worked on and is causing me a bit of grief.

the problem is once turned on it starts up ,fans run, and display works but after around 10 - 15 seconds it shuts down and i get 12 flashes from the power indicator.

i was reading a different post from a while back and it confused me a bit as this is a sound sos error and things led to the a board then the p board.

just a bit confused and would appreciate some assistance.

thanks
David

[datylor992]

Re: Panasonic TH-50PZ81B

It seems that you may have a faulty signal PCB.
Disconnect the Fan PCB and see if the set remain on for more than 15 mins.

[Alastair E]

Re: Panasonic TH-50PZ81B

It seems that you may have a faulty signal PCB.
Disconnect the Fan PCB and see if the set remain on for more than 15 mins.

Disconnecting the fan-pcb will lead to a different SOS (5?) and no start-up.

[vaxthehunted]

Re: Panasonic TH-50PZ81B

thanks for getting back to me,

i have tried dissconnecting the x and y (just to check them) they both fed back the relevent sos flashes , the trouble is i checked the speakers and main board they seem fine have not yet tested the power board (due to dropping multimeter down around 10 solid stairs and smashing it.) surely if it starts and powers up it shouldnt be the power board. im quite possibly very wrong but i am used to nice 3 - 5 board lcd tv repairs.

[datylor992]

Re: Panasonic TH-50PZ81B

I have disconnected the Fan PCB in a TH-46PZ85U because when this PCB is plugged in the set is not coming on but giving 11 blinks.
I have an external fan on the unit and it is operating good but sometimes the picture becomes solarized. I think that my problem is on the Video signal board since this board is common to the TCON PCB and the Fan PCB.

Could anyone help.

[Alastair E]

Re: Panasonic TH-50PZ81B

I have disconnected the Fan PCB in a TH-46PZ85U because when this PCB is plugged in the set is not coming on but giving 11 blinks.
I have an external fan on the unit and it is operating good but sometimes the picture becomes solarized. I think that my problem is on the Video signal board since this board is common to the TCON PCB and the Fan PCB.

Could anyone help.

I would say you have a problem on the SC board--One of the sub supplies derived by the DC/DC converter is not stable....

What picture conditions does it solarise?--Bright scenes?

How many hours on the set? V-SUS and Vda Correct?

[tw2005]

Re: Panasonic TH-50PZ81B

thanks for getting back to me,

i have tried dissconnecting the x and y (just to check them) they both fed back the relevent sos flashes , the trouble is i checked the speakers and main board they seem fine have not yet tested the power board (due to dropping multimeter down around 10 solid stairs and smashing it.) surely if it starts and powers up it shouldnt be the power board. im quite possibly very wrong but i am used to nice 3 - 5 board lcd tv repairs.

Have you tried running it with speakers disconnected?

Also since these have PSU issues with the MC201,301 modules one of which produces the 15V there's a possibility the 15v is dropping out and causing 12 blink in error.

A long shot but the flow chart for 12 suggests, speakers, A board or 15v issue and follow 2 blink chart which makes me wonder if you should do those modules first?

While this is apart it'd be worth doing those ceramic caps on those modules.