panasonic TX-P42X20B flashing red

[craig417]

Re: panasonic TX-P42X20B flashing red

Here is the service manual that covers this tv model, sorry I did not upload earlier. Hope it may be of some help. First try at uploading attachment so hope I get it right.

[karlpowell]

Re: panasonic TX-P42X20B flashing red

nice one Craig, I can disconnect the A board but not from P7 as then i don't hear a click and I don't get any voltages from the P board .

[karlpowell]

Re: panasonic TX-P42X20B flashing red



this is what i get compares to what the servive manual says.

[tom66]

Re: panasonic TX-P42X20B flashing red

The signals are present to turn the outputs on, but they are not coming up. Hmm. Since SOUND+15V is present, it sounds a lot like the processor on the power board is not turning on the outputs for some reason. Can you check the F+15V just as the set throws the ten blink code?

[karlpowell]

Re: panasonic TX-P42X20B flashing red

F+ on P6 pin 9 and 7 are both +15.8 V

[tom66]

Re: panasonic TX-P42X20B flashing red

This is different from previously measured. Are you certain?

[karlpowell]

Re: panasonic TX-P42X20B flashing red

i did the test this afternoon as I have had to take the set into work ( the Mrs was complaining about it in the back room ) but if you look at the above picture i have done pin 9 and 7 are both +15v..


I WILL DOUBLE CHECK THIS AGAIN IN THE MORNING IF YOU LIKE .


Just reading your upper post there is NO +15v on the SOUND+15V (pin 1/2)..... only +15v on pin7 and pin9 F+

[tom66]

Re: panasonic TX-P42X20B flashing red

Right now, if those measurements are good, everything appears to be working on the P board side, so the problem is quite possibly the A board.

[karlpowell]

Re: panasonic TX-P42X20B flashing red

is it worth trying to fix the A board or should I just find a replacement for it ?

[tom66]

Re: panasonic TX-P42X20B flashing red

You're losing me here. Previously, you have +15V on SOUND+15V, and nothing on F+15V. Then, you have voltage on both. Now, you have voltage on F+15V, but nothing on SOUND+15V.

Please go back, get the TV into 10 blink state, and measure each pin along that connector again so we can be sure if voltages are there or missing.

[karlpowell]

Re: panasonic TX-P42X20B flashing red

please ignore all the test before today the above picture is 100% correct

[tom66]

Re: panasonic TX-P42X20B flashing red

Have you gone back and retested them all?

[karlpowell]

Re: panasonic TX-P42X20B flashing red

P6
pin1 (sound +15v) = 0v
pin2 (sound +15v) = 0v
pin3 (p+15v) = 0v
pin7 (f+15v) = +15.8v
pin9 (f+15v) = +15.8v

P7
pin1 (standby 5v) = +5v
pin3 (s0) = 0v
pin4 (s1) = 0v
pin7 (panel main on) = 0v
pin5 (tv sub on) = 0v
pin11 (all off) = 0v
pin8 (stb-5v 0n) = 0v
pin9 (sos p4) = 0v
pin12 (main-sw) = +5v
pin14 (main sw) = +5v

[tom66]

Re: panasonic TX-P42X20B flashing red

pin11 (all off) = 0v
pin7 (panel main on) = 0v
pin5 (tv sub on) = 0v

OK, so for some reason the A board isn't telling the P board to turn on...

[karlpowell]

Re: panasonic TX-P42X20B flashing red

so would an A board swap fix this or could this still be a P board fault

[tom66]

Re: panasonic TX-P42X20B flashing red

We can prove that the P board is working. You will need to get hold of some 100 to 470 ohm resistors. Can you get those...?

[karlpowell]

Re: panasonic TX-P42X20B flashing red

Yes, Please give me the exact values and how many i need and ill pick them up in the morning .

[tom66]

Re: panasonic TX-P42X20B flashing red

Any value from 100 to 470 ohm is fine.

[karlpowell]

Re: panasonic TX-P42X20B flashing red

OK , i have a 200 ohm here

[tom66]

Re: panasonic TX-P42X20B flashing red

Do you have three?