Panasonic TX-P42GT20B - Stuck Stby

[tw2005]

Re: Panasonic TX-P42GT20B - Stuck Stby

ok i have one on order "should" be here tomorrow.
First of all am i ok just to put it in, connect it up and hope for he best or did i read some where in your long thread about the buffer board making it go popo again or am i just getting my wires crossed (for want of a better phrase).
Second if all is well do you or Tom want the original board?

I'm in Oz Tralia mate, I got 6 of them for 50" already , dunno what I'm going to do with them , thanks all the same.

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

ok i have one on order "should" be here tomorrow.
First of all am i ok just to put it in, connect it up and hope for he best or did i read some where in your long thread about the buffer board making it go popo again or am i just getting my wires crossed (for want of a better phrase).
Second if all is well do you or Tom want the original board?

[tw2005]

Re: Panasonic TX-P42GT20B - Stuck Stby

SC Disconnected
P11 pin 4 = 15.58v
pin 1 = 201v
P2 pin 1 = 207v

SC Connected -
P11 pin 4 = 15.58v
pin 1 = 0v
P2 pin 1 = 0v

I believe that is a strong indication SC is short. If it shows voltage at the SS when the SC is disconnected and nothing when connected then SC is the issue I feel. Will replacing the SC fix everything, no idea, but that's the evidence you have provided.

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

How about p11? And it's going to be around 200V and may only be there momentarily if the TV is shutting down

SC Disconnected
P11 pin 4 = 15.58v
pin 1 = 201v
P2 pin 1 = 207v

SC Connected -
P11 pin 4 = 15.58v
pin 1 = 0v
P2 pin 1 = 0v

[tw2005]

Re: Panasonic TX-P42GT20B - Stuck Stby

So if I buy a working SC board then all will be working?

i dont seem to be getting any V at P2 with sc disconnected,

How about p11? And it's going to be around 200V and may only be there momentarily if the TV is shutting down

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

i dont seem to be getting any V at P2 with sc disconnected,

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

So if I buy a working SC board then all will be working?

[ReeceyBurger123]

Re: Panasonic TX-P42GT20B - Stuck Stby

Q661 is the issue then dragging the whole SC into the dirt.

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

on q661 it beeps on all 3 legs
on sc nothing

[tn245]

Re: Panasonic TX-P42GT20B - Stuck Stby

Maybe try the resistance readings again on Q661 on sc board with the new meter. From the readings you posted before and the sc light not coming on when the ss did I suspect it is shorted.

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

i have looked over the schematics but cant fathom where or on which pins/connectors i should be checking for the voltages.

also got hold of different DMM hopefully this one will be capable lol

[tn245]

Re: Panasonic TX-P42GT20B - Stuck Stby

My 3.3V is ok. I'm missing MIHO 3.3V and in fact LED 8V. But those will only come up when the MPU sends PANEL_MAIN_ON, which it isn't doing.

[tw2005]

Re: Panasonic TX-P42GT20B - Stuck Stby

Random thought, Just posted elswhere but I had an A board 10 blinker, shorted 3.3v line, SD card slot damaged and bent pins shorting out. Most likely foreign object inserted (kids?)

[tn245]

Re: Panasonic TX-P42GT20B - Stuck Stby

I'm going round in circles a bit. 10 blinks is sub5V, sub3.3V, sub9V, F15V, Tuner Power, MIHO 3.3V, LED 8V, FRC 3.3V.

Out of that list the only one I find missing when I get the 10 blinks is MIHO 3.3V. (though it is there when D5/A31 disconnected)

MIHO 3.3V is derived on the A board from S_15V from the P board. S_15V looks to be turned on when the P board gets the Panel_Main_On signal which comes from the D board. The D board seems to send that signal by default when disconnected from A board, but A board (I think) tells D board whether to send this signal via PANEL_STBY_ON through D5/A31.

So it looks like my A board is not giving the signal to the D board to turn the panel on, and is then giving a 10 blink SOS when it doesn't sense MIHO 3.3V.

[tn245]

Re: Panasonic TX-P42GT20B - Stuck Stby

Sounds like it's going to be on the A - board. How close are you guys to each other?

Not very, sadly.

So with D5/A31 disconnected I've got my S_15V at the A board and that's when I get white screen and it stays on. With it connected S_15V never comes up. No S_15V must be what is triggering the 10 blinks SOS.

[tw2005]

Re: Panasonic TX-P42GT20B - Stuck Stby

In my case I know the P and SC boards are good because I have had them running in another set. Also with D5/A31 disconnected it is turning on with full white screen. As soon as D5/A31 reconnected I get 10 blinks.

Sounds like it's going to be on the A - board. How close are you guys to each other?

[tn245]

Re: Panasonic TX-P42GT20B - Stuck Stby

In this thread 10 blinks on a VT20 turned out to be D board:
https://www.badcaps.net/forum/showthread.php?t=59032

I can confirm that with D board disconnected from P board I get 10 blinks. So assuming your sc board is ok I think D board looks likely, but do check sc carefully because it seems to commonly cause 10 blinks too.

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

still giving me 10

[tn245]

Re: Panasonic TX-P42GT20B - Stuck Stby

Yes, everything else connected as usual, but D5/A31 disconnected I'm getting white screen and leds on sc+ss lit. Odd because I'm sure I was getting the 10 blinks previously with D board disconnected as I stated in my earlier post but this is the state of play now. Possibly at that point I had D board disconnected from P board too.

[benjamin.d.bird]

Re: Panasonic TX-P42GT20B - Stuck Stby

is that with just D5/A31 disconnected?