Lg 50pk590

[diif]

Hello, i have an LG Plasma here with an EAY60968801 PSU.
I have read the threads with the same PSU and there is a repair kit i can buy, before i purchase i was hoping someone would confirm, or help me confirm this should sort the problem.

The standby light comes on when i plug in the TV. When i press the power button on the remote i hear two clicks and the screen flashes white for less than a second then goes off. There is another click and the Tv goes back to standby.
Thanks.

[sordids999]

Re: Lg 50pk590

firstly you can check various supply voltages such as Vs, Va, VSC, Ve

[diif]

Re: Lg 50pk590

Thanks sordids999

VS=201.4v
VA=60.9v
M5V=5.07v

These seem to be spot on.

I've just read on the Coppell website, that if all of the cables are disconnected apart from the AC then it is plugged in, a click followed by one or more within a second indicate a faulty PSU.
I got 3 clicks, so i guess it is faulty.

[PowerAmpFreak]

Re: Lg 50pk590

Check the 3 power resistors in the top right corner of the PSU.

[Hamie]

Re: Lg 50pk590

Does the vs and va stay on with the y-sus disconnected?

[Hamie]

Re: Lg 50pk590

A good way to test the PSB is to buy a 200w service light bulb (maplins sell them) and solder it to the vs test point and ground.

Furthermore if the 5watt resistors test good ive not heard many other types of failure for this PSB. Personally I've never seen the diode or ic go bad.

[diif]

Re: Lg 50pk590

Thanks guys, I've just measured the three resistors and get 10.5, 10.4 and 10.2 ohms.

Is the y-sus the board on the left ? this is my first plasma i have worked on.

[Hamie]

Re: Lg 50pk590

I take it those measurements are in circuit?

[Hamie]

Re: Lg 50pk590

With the Ysus disconnected does the vs and va stay on in the power supply?

[diif]

Re: Lg 50pk590

Yes i measured in circuit. I then removed one from the board and got the same.
So i connect the Zsus but leave the Ysus disconnected, then check the VS VA ?

[Hamie]

Re: Lg 50pk590

Yes remove the ysus, plug the x back in and power on.

[diif]

Re: Lg 50pk590

Thanks Hamie, i am a little confused now. I have identified the Ysus and Zsus, which is the x ?

[Hamie]

Re: Lg 50pk590

Sorry z is the x.

[diif]

Re: Lg 50pk590

Thanks Hamie, yes VS and VA still present with just the Zsus connected.

[Hamie]

Re: Lg 50pk590

Ok finally disconnect the buffers from the ysus and power on.

[diif]

Re: Lg 50pk590

Thanks, I appreciate your patience Hamie, buffers ? the big long board with the ribbon cables ?
Zsus still connected or just the Ysus with buffers disconnected ?

[Hamie]

Re: Lg 50pk590

Yip everything now connected apart form the buffer boards that connect to the ysus.

[diif]

Re: Lg 50pk590

Cheers, VS and VA still present.

[Hamie]

Re: Lg 50pk590

Ok check vsc, -vy, and zbais

They should match your panel sticker.

Like this.



Vsc, and -vy are located on the ysus.
Zbais on the zsus.

-vy is measured sometimes across a resistor, but is marked with + and -

All in dc volts.

[diif]

Re: Lg 50pk590

With or without the buffer connected ?
i did see those on my sticker and wondered where the points were.