Panasonic P58V11B 8 and 12 blinks error "fix"

[Biruslapio]

Bought this TV used not working, panel flashed briefly on power up and it was blinking 8 times, a quick look on SS board revealed a common fault on the 3uF 250V capacitors, C201 to C205 (C1620X in the service manual), the solder joints were all cracked, C201 and C205 pins were darkened and some sparking had occurred on them, C201 was split open and clearly overheated in its last hours, replaced that one and resoldered the others, 8 blinks fixed.

Also the previous owner broke the antenna connector by taking the TV out of the wall mount forgetting to unplug it, I desoldered the tuner from A board and will replace it when I have one (ENGF7605GF).

Then the TV worked for 3 seconds, HDMI 1 showed up, panel seemed fine and it decided to pull a 12 blinks error.

When PANEL_Main_ON is triggered to 3.3V the PFC relay soon shuts off, 15V and 5V appear for a split second, then 12 blink code, sometimes the PFC relay did not trigger at all.

Here's the blink error code history that it did, then what I did after that:
8 Blinks > replaced capacitors on SS, desoldered tuner
12 Blinks > removed A, SS and D boards to check for shorts and bad solder joints, nothing wrong, put them back.
5 Blinks > isolated SC,SS and C from D board, nothing helped, so I reassembled the connectors.
3 Blinks > forgot to plug Vda cable
2 Blinks > ??? back to 12 blinks now

Pin number / Label / Switching ON / After PFC relay shuts off / Blink code starts

P6 (to A board)
01 15Vs / 15.63V / 1.44V / 0V
02 15Vs / 15.63V / 1.44V / 0V
03 15Vs / 15.63V / 1.44V / 0V
04 GND
05 GND
06 GND
07 F_STBY / 15.65V / 15.65V / 0V
08 F_STBY / 15.65V / 15.65V / 0V
09 F_STBY / 15.65V / 15.65V / 0V
10 GND
11 GND
12 GND

P7 (to A board)
01 15Vc1 15.63V / 1.44V / 0V
02 15Vc1 15.63V / 1.44V / 0V
03 GND
04 GND
05 STBY5V 5.058V / 5.062V / 5.062V
06 F_STBY_ON 3.27V / 3.27V / 0V
07 ECO_ON 0V / 0V / 0V
08 ALL_OFF 2.93V / 0.014V / 0V
09 STB_SW 0.958 / 0.155V / 0.155V
10 5Vc 5.039V / 0V / 0V
11 AC_LOW 0.39V / 0V / 0V

P25 (to D board)
01 15Vc2 / 15.63V / 1.44V / 0V
02 15Vc2 / 15.63V / 1.44V / 0V
03 GND
04 GND
05 5Vc 5.039V / 0V / 0V
06 5Vc 5.039V / 0V / 0V
07 GND
08 GND
09 STBY5V 5.058V / 5.062V / 5.062V
10 GND
11 PANEL_Main_ON 3.31V / 0V / 0V
12 PS_SOS 0V / 0V / 0V
13 Vda_LOW 0V / 0V / 0V

I thought it was a power supply fault because of the multiple blink codes, like it was trying to power up but the power supply refused, soon I discovered it was the other way around, the main board first detects 15V missing and start the 12 blinks, but sometimes by random chance it detected 5V missing first.

PFC = 385V until relay is OFF
VS and Vda are good
STB_SW = 4.93V with main power switch OFF

D board is disarming PANEL_Main_ON before the TV even finishes booting, I cut Pin 11 from D25 to prevent any internal shorting and used a wire jumper from P7 Pin 6 to P25 Pin 11.

Unplugged SC, SS, Vda, D25 and D3, effectively only powering up the main board, used the jumper from F_STBY_ON 3.3V to PANEL_Main_ON, the PFC relay switched correctly then it shut down with 1 blink error, this TV does not work with main board only, you need D board too.

Only A and D board + fans test with jumper, it worked for about 10 seconds, before shutting down into 4 blinks POWER_SOS, so something is drawing too much current from the PSU maybe?

IC3001 was getting warm during these tests, about 65 Celsius in those 10 seconds, 5V and 9V VCC were present and stable, it's an A/V switch but there was nothing at any of those inputs nor it was selected in the TV, it was the only component that seemed to be heating on A and D boards.

Ignored that, plugged all the connectors back and I was able to go into the menu and factory reset, now it's been working for some hours, on stand-by VSUS and Vda shut down correctly, good.

But something is still wrong with one of the boards, I cannot identify it, nothing in the service manual can help me with this fault, apparently IC3001 is fine, I will keep testing the TV like this and if something bad happens I'll update.

This is a very similar problem to my other P50VT20B TV, it doesn't trigger at all PANEL_Main_ON and blinks 12 times, next time I mess with it gonna try to feed 3.3V to that pin.

[Biruslapio]

Re: Panasonic P58V11B 8 and 12 blinks error "fix"

Update: The TV worked for about 30 hours or so, then it shut down, 1 blink every 3 seconds, Unknown Error.

What gave me hope that it was not the A board, which is incredibly rare and expensive was that, when it failed, the screen shut down, but sound still played, green LED was on, then when I tried to reboot it, unknown error, so it was something related to the D board.

The original failure was PANEL_MAIN_ON failed to remain High/3.3V, according to the service manual that signal comes from the main processor in D board.

So the D board of this TV has no notable points of failure, all SMD components, there was no shorts, so I tried reflowing, no change. Bought an used D board, removed the jumper, reconnected the wire, it's back in action.

So this shows that for this V11 series when only PANEL_MAIN_ON is being problematic, D board is about to fail.