Panasonic TC-P42X1 Plasma 12 Blinks

[tw2005]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

No short, and disconnecting all of those cables still gives 2 blinks.

Well although no change at least for sure P or A and not anything else for what it's worth.

[tom66]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

AC detect is working then, so something that power MCU detects it does not like.
Damnit I wish there was a flowchart for its internal logic program, it's probably really simple, but nope...

[tw2005]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

How about some random stuff like checking PR700 FUSE , PR702 FUSE.?

[tw2005]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

The “PANEL_STB_ON” is used to turn on the 3.3V regulator (IC9004) on the A board. The output voltage is
applied to the “Panel” CPU on the A board (Formerly located in the D board).
The Panel CPU on the A board outputs the “PANEL_MAIN_ON” Command (3.2V) to pin 11 of connector
P25 on the P board.
The PANEL MAIN ON command turns on the power supply circuit that outputs the Vsus, Vda, 15V, and 5V.

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

Well definitely not getting the PANEL_MAIN_ON on that pin. Not showing a short on there either. I'll keep looking.

Checking pin 99 (IVDD) of IC9003 Panel Micom, I get 3.3V when power button is pressed, however nothing outputs on pin 75 (PANEL_MAIN_ON).

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

Hmm this A board not available either, should I try removing the entire Audio IC2109?

Game Over. Need new A Board.

[tw2005]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

Hmm this A board not available either, should I try removing the entire Audio IC2109?

Game Over. Need new A Board.

I take it you tried to remove that and destroyed the pads?

[tw2005]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

There's 2 other boards you'd get away with but you will lose the third HDMI port on the side. The PX14 has a PC D-SUB 15PIN, The rest should be the same. Maybe try and get the faceplate off whoever is selling the board if they have it.

TNPH0800, TNPH0800AC, TNPH0800AE

There was an Ebay list for repair but probably too late if the board is damaged.

42PX14

AE revision 42"

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

I take it you tried to remove that and destroyed the pads?

Yes the body of the chip is soldered too

I thought maybe there was still a fault from the chip like you said but there wasn't it still gives 2 blinks now.

Thanks for the info Ill check it out!

Do you think it's likely the Panel MCU chip is bad, or that is not getting a signal it needs from somewhere else?

[tw2005]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

Yes the body of the chip is soldered too

I thought maybe there was still a fault from the chip like you said but there wasn't it still gives 2 blinks now.

Thanks for the info Ill check it out!

Do you think it's likely the Panel MCU chip is bad, or that is not getting a signal it needs from somewhere else?

No, I can't see where I suggested there was still a fault from the audio chip. I simply copied and pasted the power on sequence just in case that gave any more clues. Was curious about whether all the fuses around the 15v cct were good.

I think Tom alluded to a MCU or firmware issue but if it never sends the panel on then the 15v won't turn on reading the description so you'd expect to see that at least first and then if the 15V never came up then 2 blink.

What also has me curious is how it generates a 12 blink when nothing is shown in the schematic and i saw nothing off the audio chip with the pin for FAULT showing NC.

I'm thinking since this board is stuffed, would it be worthwhile attempting to inject 3.2 volts for the panel on and see what happens and/or maybe feeding the f15V to the 15V det and see if it tricks it. Not sure of its current capacity so yeah, could be dodgy. random ideas really.

I'd be interested to see what Tom thinks or what tricks he may have. I've messed with eeprom swaps but never had to get down to this on a Panasonic to get it going so a bit unsure if any damage can happen.

[tom66]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

One of the things I've done before is to check the various inputs into the panel MCU to see if there is a SOS signal there or missing.

Note sometimes the audio amp IC will use I2C to communicate an error code, the error can be a bad output stage, shorted transistor, over-temp, under-volt etc.

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

OK yes after applying 3.2v to pin 11 of P25 it kicks on the rest of the PS.

The panel lights up faintly, not picture, but the TV does stay on.

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

I had forgotten to plug connector P35 back in, now I get this

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

Unplugged to make sure cables were seated, now getting 7 blinks.

[tom66]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

I've had 7 blinks on a PZ80 caused by not an SC board fault but by a loose connector on the address boards (they run along the bottom edge of the plasma panel.) You may also get 5 blinks due to 5V DET failing (this can also be due to a bad panel shorting 5V though...)

The yellow bar would indicate to me you have at least one loose connector.

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

I immediately thought bad panel when I saw half the screen missing and the yellow stripe, what do you think of that?

[tom66]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

I immediately thought bad panel when I saw half the screen missing and the yellow stripe, what do you think of that?

I have had that with a loose connector on the PZ80s. It's very rare to get a completely dead half of a screen with a bad panel. Yellow bar is OK, if it can display something with no random lines in the bar. Statistically improbable to get every 2nd line to fail .

[kevinm34232]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

Now, If I disconnect SC20 (the small ribbon going from main to SC), I won't get the 7 blinks.

[tom66]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

Check ribbon cables for tears or damage, especially at connecting ends.

[tw2005]

Re: Panasonic TC-P42X1 Plasma 12 Blinks

I had forgotten to plug connector P35 back in, now I get this

Did anything arc when you connected p35? Not something I would reconnect straight away after a shutdown only becasue you can and i have destroyed the panel.

Well, you have a good PSU, makes it a bit easier, don't like all these surprises, reminding me of my P42X20 (C2)