Panasonic Plasma TH-50PX600U – Weird behavior

[Anonymous]

I calibrated old TH-50PX600U. After calibration in Service Mode I couldn’t get out from Service Mode by turning TV OFF, so I used “C” button on service remote, TV made self check and after then I unplugged TV and plugged it again. Of course I reset everything in user menu, so I set all controls again from my notes and checked if calibration result are the same to be sure that nothing changed in SM.

Couple days ago my client e-mailed me that TV has a CHK# 00000000 and a number on the right of the screen.
I asked him to unplug TV, plug again.
He answered: “No couldn’t do it. Can’t access menu from remote or on TV.”

1. Why this CHK# 00000000 returned? I didn’t leave it this way. After calibration we were watching TV for ~30 minutes
2. How to remove this info from the screen? I can’t find anything here in our forum about such problem.
3. Does anybody know what could happen to this TV?
It is really weird and I have no clue what can I do.
So:
According to my client, 20÷30 minutes after I left his house after calibration this yellow/green information pop out on the screen: CHK XX 00000000 on the left and YY number on the right. Position of this information changes vertically but it stays in upper 1/3 of the screen. Does TV returned to Service Mode by itself?

TV doesn’t respond to any command from remote neither main unit except “Power OFF” so I couldn’t do anything. I tried original remote, service remote – nothing.
So we unplugged this TV for 5÷7 minutes and plugged again. TV started with this yellow/green information on the screen, but – at my surprise – I could change input from remote. I switched to HDMI1, tried to go back to Component and – nothing. Nothing at all. TV didn’t listen to any commands at all again. I tried several options – noting.
So I unplugged it again for 20÷25 minutes. After powering TV ON, I was able to go to menu and set all controls according to my data after calibration, so I got calibrated picture back.
I tried to go to service menu by pressing Volume and Info, but as soon as volume went down, TV stopped answering any command (except power ON/OFF)

Why this TV doesn’t answer to commands neither from remote neither from panel itself?
What can I do to fix it?

Last week I called my client, asked him to turn off TV for 30 minutes and press POWER and OK simultaneously on the panel, then press the VOL button on the panel to clear the CHK. (Advice from my friend Barry) He didn’t succeed.
I will go to his house tomorrow to try some options, but I have following questions:
1. Why this TV doesn’t respond to any command from remote neither main unit except “Power OFF”?
2. When TV is in service mode it normally respond to commands from remote or main unit. Why this one doesn’t?
3. Why this TV responds to commands after is in OFF state some time and doesn’t after is ON for some time? Timer? Heat?
4. After calibration in Service Mode I couldn’t get out from Service Mode by turning TV OFF, so I used “C” button on service remote to get out from Service Mode. Did I messed up something doing this?

I reviewed all my old notes related to this and similar models and still have no clue WHY this TV doesn’t listen any commands. Even if it is still in Service Mode it SHOULD listen to commands, doesn’t it?

Any help will be appreciated.

Best Regards

Topic

[Gregg Loewen]

correct in hitting C.
You do not unplug…you hold down the power button on the panel until it resets.
Not sure if this is the cause ??

[Anonymous]

Done.
I tried several options. No trick done from user mode helped.
Finally I managed to get into SM and it made me happy. Being there I could navigate through SM using remote. It made me even happier.
For some reason panel was in service mode, stuck in checking stage.
I figured out, that panel IS STILL “CHECKING” , even when I am in SM, so when I went back to SM by pressing A and B buttons (Volume and info didn’t work so without service remote I couldn’t do anything) I pressed “C” button.
Panel performed “self check”.
I pressed power button on panel and kept until click, released and waited. Panel went back to ON after 3÷5 seconds by itself without CHK0000 on the screen.

I set controls on UM to calibrated values, check picture, play with Bluray, total ~40 minutes and never went to any problem, so I think that I have answers to my questions:
1. Why this TV doesn’t respond to any command from remote neither main unit except “Power OFF”?
A: Because is still in SM stuck in “Checking”
2. When TV is in service mode it normally respond to commands from remote or main unit. Why this one doesn’t?
A: Because is still in SM stuck in “Checking”
3. Why this TV responds to commands after is in OFF state some time and doesn’t after is ON for some time? Timer? Heat?
A: Because is out of “Checking” stage for while.
4. After calibration in Service Mode I couldn’t get out from Service Mode by turning TV OFF, so I used “C” button on service remote to get out from Service Mode. Did I messed up something doing this?
A: No. But I messed up because I unplug TV instead of pressing power button on panel itself. I was thinking that if power button on remote doesn’t work, the only option I have is to unplug TV. I was wrong.

Costly lesson. I hope that – if someone has to do something with old panel – no one will fell into such trap.
DON’T UNPLUG THIS PANEL WHEN IN SM.

Thanks Gregg

_________________
Zygmunt Wojewoda
Perfect Home Theater
Tel.: 617-965-6984

[Gregg Loewen]

hey Z.
Nice write up.

[Author]

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