LG PDP42V7 Plasma TV - sound, but no picture.

Graeme · Joined: 05 Nov 2007 Posts: 10

Hi all.

This is an LG Plasma screen TV.
Full model number PDP42VB74013.

With a couple of DVD players connected to the AV inputs, you can power-up the set and select the input you want all with the remote control, however, there is no picture at all.

Not even on-screen graphics.

Set will not start at all, if the YSUS and ZSUS boards are connected to the PSU, and there was a blown fuse on each of these boards.

I replaced the fuses, but then the set refuses to start at all.
If you unplug the PSU feeds to the YSUS and ZSUS boards, the set starts, but with no picture(as to be expected), yet you can get the sound with no problems.

I suspect that the main PSU board, part # 3501Q00156A Rev. A is faulty, however, I would like some confirmation.

A search of the net has resulted in the hint that YSUS, ZSUS and PSU boards should ALL be replaced.

Thoughts?

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

there is a modification kit for this fault, contains 3 pcbs all of which must be replaced, amazingly cheap, check out http://www.chsinteractive.co.uk/electrical-components/misc/pdp42v7-pcb-repai-kit-lg-6871qch053g-ctrl-6871qzh041b-zsus-6871qyh036d-ysus.htm

minnie · Joined: 18 Aug 2005 Posts: 2880 Location: Hell

Contact LG, most LG set are 2 year warranty. But Gary's correct, their cheap!

Graeme · Joined: 05 Nov 2007 Posts: 10

Thanks for the link!
Checking it out...
Smile

G.

gib123 · Guest

i have a hitach 42pd3200 plasma with this same fault, have done some research and found that the ysus board and zsus board in this kit will fit but i cant find a ctrl board in my tv that matches the one in this kit, any help? would i have to buy a seperate control board if any? or would a change of the zsus and ysus boards be sufficient?

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

the control board must be replaced with the new one, it is mounted behind the av input board, the replacement one looks different and is physically smaller but does the same job, dont forget to swap the heatsinks over.

dave1234 · Guest

I have a similar problem. I have a rebadged lg using the 42v7 panel. When I plug in the tv, I get the red standby light, when I press the power button, the light changes to blue, then I get a clicking noise, and the light changes back to red, it then clicks again turning blue... This process keeps repeating itself, until I unplug the tv. The clicking noise is coming from the power supply board.

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

check to see if any of the fuses have gone on the sus boards if they have fit the kit

dave1234 · Guest

You don't think that its the power supply? Not sure if I should buy a ps and the ysus repair kit. I see a lot of these kits for sale, but they are in the UK, and I am in Canada. Would these still be compatible?

gary · Joined: 05 Apr 2005 Posts: 584 Location: MANCHESTER, uk

have you checked the fuses on the sus pcbs? a blown fuse will mean the power supply has no work to do and so the set will not run. i must admit i have only seen about 20 of these sets and dont know how reliable the psu is but i do know the sus boards are very unreliable, have never had to change anything else.