LG 60PB5600 Turning Off

[ShaunM]

LG 60pb5600 plasma TV turning off after sound is initiated on startup. I thought that this was the YSUS board so replaced it with a new one. Unfortunately, there was a popping noise and then the TV returned back to this original problem.

After research, I figured that I should had also replaced the Y-Buffers at the same time as the YSUS. Ordered these three new boards from Sears but, once installed, the problem persists. No popping noises or anything though. It powers up when I push the button and once the sound comes on it immediately turns off? Any ideas?

I should also add, the reason I originally thought that it was the YSUS is because the tv power will stay on if I disconnect the YSUS board connection from the ZSUS(The YSUS power is routed through the ZSUS on this TV).

[heavymachines]

Re: LG 60PB5600 Turning Off

pics of entire back of set?

[ShaunM]

Re: LG 60PB5600 Turning Off

https://imgur.com/a/KJBFi

[ShaunM]

Re: LG 60PB5600 Turning Off

Was not sure I could directly upload the TV pics to this server. Here they are.

[dick_barton]

Re: LG 60PB5600 Turning Off

Try running the test pattern by removing the ribbon cable from the logic board (little board in the middle of the set) which goes to the mainboard and jumper the two pads marked EXT_AUTO_GEN on the logic board.

[ShaunM]

Re: LG 60PB5600 Turning Off

I shall try. What is the best way to jumper those pads?

[ShaunM]

Re: LG 60PB5600 Turning Off

So, do I just run a conductive wire from the 2 pads I marked with a red box in the attached picture?

[heavymachines]

Re: LG 60PB5600 Turning Off

You can hold a paper clip to it or soldier a jumper wire to it. Probably best to soldier it so you don't slip and short something out. Simply bridge connection.

[heavymachines]

Re: LG 60PB5600 Turning Off

So, do I just run a conductive wire from the 2 pads I marked with a red box in the attached picture?

Yes.

[ShaunM]

Re: LG 60PB5600 Turning Off

They are actually not pads but holes which a paper clip can fit through(as suggested). Just want to make sure I do this right because they are holes(not pads) and I can see the paper clip ends protruding through the back end of the board.

By the way, a HUGE thanks for the help. I have already bought 2 YSUS boards and Y-Buffers and do not want to purchase a power board if it is not needed.

[heavymachines]

Re: LG 60PB5600 Turning Off

paper clip will work if holes rather than soldier wire to pads.

[ShaunM]

Re: LG 60PB5600 Turning Off

Same issue. Power comes on and tv turns off as soon as sound is initiated.

[dick_barton]

Re: LG 60PB5600 Turning Off

You did remove the ribbon cable from the mainboard before doing the test?

[ShaunM]

Re: LG 60PB5600 Turning Off

Yes, I did. I did keep the power cable from the power board connected to the main board though.

[heavymachines]

Re: LG 60PB5600 Turning Off

i believe power cables to main needs to be disconnected as well i have done this before on plasma and main is to be totally disconnected. The board you're jumping will generate test patterns.

[ShaunM]

Re: LG 60PB5600 Turning Off

OK. Shall try that now.

[ShaunM]

Re: LG 60PB5600 Turning Off

With both the ribbon and power cable disconnected from the main board there is no power on at all. Even the red stanby light does not illuminate. You can hear the power board click when it is plugged in but the power button from both the remote and on the TV will not power on the TV. Whereas before, the TV will turn on until the sound starts and then immediately turns off.

[heavymachines]

Re: LG 60PB5600 Turning Off

it is expected remote won't work as the main is disconnected. with main disconnected and Auto Gen is jumped it will automatically turn itself on and generate pattern. This is how to rule out main issue or problem in y or z.

[ShaunM]

Re: LG 60PB5600 Turning Off

Actually, upon looking at the back of the TV, it looks like the logic board actually received power from the main board and there is no direct power cable from the power board to the logic board.

[heavymachines]

Re: LG 60PB5600 Turning Off

clearly you still have a problem in y or z sustain, since you swapped out y and buffers i am leaning with you got bad replacement or the z is blowing things. You will need to do short test on igbts on y and buffers and the z. And before you blow your new parts you should hook up bulbs in series to prevent blowing your replacement parts.