Panasonic TX-P42GT20E 3D , does not turn on!

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

What voltage you measure at pin 7(STB5V) of IC5482 and also what resistance you measure between pin 8(STB3.3V) of IC5482 and GND?

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Thx for your help!

4.5v and 200 Ohm

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Ps , thats with a white screen!

"Edit" ---> Froze the board and plugged in the mains , ic5482 immediately starts defrosting while the other parts stay frozen! Think that this is our problem?

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Can be. Do IC5482 feel hot when you touch against it? Probably, because it starts defrosting so fast. I don't know what the exact value for the resistance should be, but 200 ohm seem low. Remove L5481 and then measure the voltage and resistance again at pin 8(STB3.3V). Also freeze IC5482 again to see if it still stars defrosting so fast. Removing L5481 takes away all the loads from the STB3.3V supply

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Will do that when i get home! thx again for the help!

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Its still defrosting fast after removing L5481 and now i have 160 ohm.

Pin 7 is still 4.6 volts.
Is there a similar IC like this that i can use? This IC is 40$ for me to order online , a new main board is 70$ :/

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Remove C5497 and measure again the resistance and voltage at pin 8. C5497 might be short. If you still measure 0V and low resistance at pin 8 and the IC still defrosts fast or feel hot to the touch, then it's safe to say it's faulty. There no similar IC like that. At that price, you might as well get a new main board

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

When i remove C5497 , do i need to bridge the connection? Or just remove it only and leave it as it is?

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Remove only and leave as is

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Will do it right away!

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Im measuring 3.1/3.2 volt on pin 8. Pin 7 measures 4.7v after removing C5497.

Tv does not turn on with D board connected to main board. , without D board i still get a white screen.

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Also , looks like Pin 8 is slowly building up in volts. It starts on 3v ends on 3.26

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

And what does the resistance between pin 8 and GND measure now?

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Also measure the resistance of C5497 that you removed

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

I lost C5497….

Im measung "OL" on Pin 8 and chassis. ( ohm )

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Those caps are so small and can easily go missing, but C5497 was shorted anyway and was pulling the STB3.3V at pin 8 down. That's why you measured 0V and low resistance before at pin 8. Next is to solder L5481 back into the board and then measure the resistance again at pin 8

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

Hmm ok. Do i need L5481 to get the tv working?

I measured again with the D board connected , i get 3.278v and 4.74v.

[Neelix]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

The STB3.3V supplies the processor that must switch the TV on with power and without L5481, the STB3.3V can't get to the processor. So yes you need it. Did you loose L5481 also?

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

No did not loose it but now I'm measuring 0v and 326 Ohm. Other voltages are lower also ( 4.5v ).

[Moreno83]

Re: Panasonic TX-P42GT20E 3D , does not turn on!

I don't get it , without L5481 I'm getting 3.27v …thats 0.03v to low. Must be a reason why? Cant i jump this connection?