Panasonic TX-P50VT50E completely dead!

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

I took a better picture. The silver line is pin6! If you follow that line you end up on JA17. The line next to the silver line is P5/STB5V wich goes to JA17 ---> R489 --> trace goes under JA14 to pin 6 of I552.

Thats all i can see.

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

In the schematics STB5V_SW_ON and STB5V are on/off on the mainboard --> Q2001 and Q2002.

You still think the fault is in the powersupply or are you also suspecting the mainboard?

[tom66]

Re: Panasonic TX-P50VT50E completely dead!

What is the part number of IC552?
Since the 5V is not being generated is it probably a failure with that IC.
The IC is likely to be custom so you will have to replace the whole power board unfortunately.

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

I also think that that IC is the problem. I even took the time to measure all the mosfets and diode's on that side of the board and they are all ok.
I can't see the name on the ic , its blurred out.

Im going to order the power supply and hope that it will fix the problem. Will let you know and thx for the advice and help Tom!

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

Ok , scrubbed the part hard with alcohol and this is the type :

SLG4K034G K176004BA

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

Do i need the exact powersupply? Mine is NOAE6KL00010.

I saw on ebay for example NOAE6KL00017 , whats the difference? Visually they look the same.

[tom66]

Re: Panasonic TX-P50VT50E completely dead!

It will probably be compatible - just be aware that e.g. a 42" power supply may not be suitable so make sure it comes from a similar model.

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

Ordered the same powersupply and will receive it tomorrow. Hopefully its the only fault.....

Im thinking that the tv had some kind of lightning/power surge problem and that it took out the IC.

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

Replaced the power supply with a brand new one but still the same issue. Tv is completely dead and measuring exactly the same!!!!

Is it the mainboard or the power button thats not working? How can i test this? Man , was really hoping that this would fix the tv

[tom66]

Re: Panasonic TX-P50VT50E completely dead!

AFAIK, the main board has been eliminated. Could be a switch, or the power board. Not sure how to tell. Maybe tw has more info.

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

I called the shop where i bought the PS. He said it comes from a defective tv with a broken panel. All PS are tested and should work. Power supply has probably run for 2/3 hours. It had a warranty label on P6 with i removed to measure the 5V and he said i can't return the PS. ( f f s )

He said that its probably a microprocessor on the mainboard that pulls the 5V down? Cant i hot start the tv on the mainboard? Shorting 2 pins for example.
New mainboard is also 100 euro :/

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

Voltage over the power button is 3.3V and the power button is ok.

[tom66]

Re: Panasonic TX-P50VT50E completely dead!

You have eliminated the main board being short by pulling the connector. Assuming your measurement is correct, you have 0V on the main board power.
I presume you have tried both switch states, just in case it's not obvious which is "on".

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

Hi Tom ,

This power supply is brand new. Its been used for 2/3 hours , not more!
I don't believe that 2 power supply's are doing exactly the same and yes my measurements on that connector are fine.
Don't forget that i DO HAVE EV5V that is going to pin6 on P6 into the mainboard. When i pull connector C11 the voltage on the power button disappears. C11 is a white flat cable thats going to the A board. ( Same kind of cable like SC20 ).

So this means that the mainboard is getting voltage from the PS , i don't know if its the RIGHT voltage though.

Yes , i opened up the connector and tested the power button. Its working perfectly.

Hope this helps in troubleshooting. IF not then ill buy a new mainboard because i want this tv to be fixed.

[tom66]

Re: Panasonic TX-P50VT50E completely dead!

Don't forget that i DO HAVE EV5V that is going to pin6 on P6 into the mainboard.

What?
I specifically asked before if you had 5V standby? You said NO!

No i don't get 5v on that wire.

So new power board has 5V?

If main is still dead, you have a dead main and power board. Could be a power surge or less likely, previous power board damaged the main board (over-voltage, etc.)

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

No no , look few pages back! I know my english is not that great so it can be confusing.

I DONT have STB5V on pin 5 from connector P6. ( on both boards ) In the service manual it says that pin 5 = STB5V_SW_ON.

I DO have 5v ( 4.6v ) on pin6 from P6 with is going to the mainboard , this is the ONLY voltage i have on connector P6.

Does this mean the mainboard is dead/short?

[Moreno83]

Re: Panasonic TX-P50VT50E completely dead!

Ok , starting to understand the schematics a bit. EV5V is going from pin6/P6 to the mainboard to Q2001 which sends a signal to IC2002 with is a peko switch that turns on the STB5V.

I do have 5V on Q2001 but not on Q2002/2004 which means IC2002 is not working. Need to find the same chip to see if the error goes away or a new board ( or troubleshooting which is hard on a mainboard ).

[tom66]

Re: Panasonic TX-P50VT50E completely dead!

Oh dear, well that's why I kept asking if you had 5V on that thick trace pin - and to try trace it back. I thought you did not have any standby. I would not have said the power board was bad otherwise.

It is probably a main board fault then, what is the marking of that pin that does have 4.6V on it? is it standby or some switch signal?

[tw2005]

Re: Panasonic TX-P50VT50E completely dead!

Hmmz , i uploaded it but its not visible.

link was for a user manual, not service,

[tw2005]

Re: Panasonic TX-P50VT50E completely dead!

Ok , starting to understand the schematics a bit. EV5V is going from pin6/P6 to the mainboard to Q2001 which sends a signal to IC2002 with is a peko switch that turns on the STB5V.

I do have 5V on Q2001 but not on Q2002/2004 which means IC2002 is not working. Need to find the same chip to see if the error goes away or a new board ( or troubleshooting which is hard on a mainboard ).

Oh dear, well that's why I kept asking if you had 5V on that thick trace pin - and to try trace it back. I thought you did not have any standby. I would not have said the power board was bad otherwise.

It is probably a main board fault then, what is the marking of that pin that does have 4.6V on it? is it standby or some switch signal?

Funny, well not really but I've only just starting digesting this and after not finding the service manual in that link, was checking to see if pin 6 was stdby 5v as I'd looked at the St50 manual which the PSU appears to be similar had 5V on Pin 6 and I did not see a direct reference to it in the posts but pin 5 was nearly about to ask what's on pin 6 until I just read these. Read your PM first I'm afraid then went off doing research.

Sounds like you're back on track but 2 P boards same result is an alarm bell suggesting not P board. Completely dead no front LED often ends up being A board.