LG 50PK590 power fault and vertical line

[Trune]

Hi guys,

Hoping you can help.

The plasma initially had a vertical line down the middle of the screen but around the same time it also started to develop a problem with powering on. It does power on sometimes, but others not... It clicks then clicks off again shortly after.

I have looked on the forum etc and found posts about the resistors in the top right of the board (eay60968801) and noticed repair kits on eBay also.
However repair kits seem to mention 2 resistors of 22ohms however this board is 3 resistors of 10 ohms. I have checked all three and they are reading 10 ohms as expected.

I also notice that a regulator 3BR1565JF and diode are in some kits (located at the centre of the middle heatsink). Is there any way for me to test these? Do I need to remove the diode to successfully test it? (As attached to the board it shows unexpected readings, but I imagine this is because it needs to be removed for accurate tests).

Any help would be appreciated, could the two problems be related? Vertical lines and power? I imagine not to be honest but need to solve the power issue before continuing troubleshooting really.

Thanks

[freakaftr8]

Re: LG 50PK590 power fault and vertical line

yes. I hate to say it but most likely what is going on is your X driver IC on the panel is shorting out, loadding down the power supply VA voltage and then power supply goes into protection shutdown. Try disconnecting the two bottom ribbon cables that run the X drivers off of the control board. These are located at the bottom of the control (logic) board. Power up, see if it shuts down now. Note the screen will be all white thou. If no problems powering up its most likely an X driver IC embedded in the ribbon cable that connects the driver boards to the panel (not replacable) to that address shorted out. Or it can be the driver board.

[Trune]

Re: LG 50PK590 power fault and vertical line

Thanks for the reply.

After taking the pics I reattached the board and the tv is staying on again at the moment (not particularly blizzard, it's been acting this way anyway).
The line is still there, and it's staying on.

As a coincidence I did some trial and error to try and find where huge fault may lie and I believe as it's a single pixel vertical line (green) in the centre it is X related or control board?

I've tried reseating connections etc.

When it plays up turning on again I will try disconnecting the ribbon.

[freakaftr8]

Re: LG 50PK590 power fault and vertical line

Its most likely the panel. LG plasmas seem to have this fault .you can always try to order a control board or try reseating the x driver cable but it may not help this issue.

[munirutech]

Re: LG 50PK590 power fault and vertical line

i think you have a bad panel is very common for lg and samsung panels and for the diode break one end to get accurate reading

[Trune]

Re: LG 50PK590 power fault and vertical line

You may be right.
Although not ideal I located which ribbon was driving the vertical section of the panel and managed to connect it to a different x-driver. Unfortunately due to what I was able to display on the screen it was unable to be 100% sure but it did appear the line was no longer present.

This would imply that it's either the centre X board or the controller. No way of verifying either without spares really.

I have given the connector on the problematic ribbon a clean and will try that tomorrow but it's unlikely.

[tom66]

Re: LG 50PK590 power fault and vertical line

Vertical individual lines are essentially always the panel. The X drivers only pass the clock, data signals and don't discriminate between individual lines.

[Jabboy]

Re: LG 50PK590 power fault and vertical line

Hi, Have u resolved this issue at all?
I have the same TV which flashes blueish colour for a second and goes off.
No picture or sound.I have tested the 10Ohm resistors and they are fine. all voltages from PSU appear normal?
any help please?