help with nexus nx422 (lg panel #pdp42x30000)

[arronius]

Hello all, I recently got a free nexus 42 plasma that will turn on but only shows a bright white flickering screen. Input, volume, and chanel buttons do nothing, remote doesn't work, and will not display any input or sound.

I originally thought it was the control board based on a post here of a tv with similar symptoms, but replacing it provided no results.

I have tested all connector voltages and they are all spot on, checked all fuses, and none of the caps appear to be bulged or leaking. When I unplugged the y sustain the screen would not turn on. When I unplugged the z sustain I got some red vertical lines.

Also when I ground the black pin of my multimeter, and put the red pin on the top of the capacitors most of them read .6 volts and slowly drop down to zero. Although on a few of the caps (4 on ysus, 3 on ps, and 1 on main) had very high voltage readings. Some of them read over 600 volts! Is this a sign of a bad cap or a crazy coincidence?

Here's some pics.http://s1370.photobucket.com/user/ar...?sort=3&page=1

[aaronwt6]

Re: help with nexus nx422 (lg panel #pdp42x30000)

The symptom you are describing is a classic Y-Sustain failure of the 42x3 and 50x3 series of LG Plasma panels. Your IPM (Intelligent Power Module) on the Y-Sustain board has failed. It can be repaired but is by no means an easy fix to swap it out. I'd say 90% plus chance that if you change the Y-Sustain out for a working one you'll be back in business.

As far as the sound goes, my guess is that you simply have not had the TV on the correct input for whatever device you have hooked up and/or cannot see what the volume is set at since the picture doesn't show.

My 2 cents but I've dealt with many of these. The LG 42x3 and 50x3 panels were used in dozens of models from that time period around 06'.

[arronius]

Re: help with nexus nx422 (lg panel #pdp42x30000)

Thanks for the reply! I was worried it might be the ysus at $110 for a used one I'm not sure it would be worth it on this tv but I might try it.

What about the insane voltages I'm getting off of some of the caps? Considering there are a few of them like this on just about every board I'm worried just swapping the ysus won't completely fix the tv.

[aaronwt6]

Re: help with nexus nx422 (lg panel #pdp42x30000)

Not sure on the voltages you are getting but the flashing / strobe effect is definitely the YSUS. I have 3 of these to repair tonight by changing the IPM which I will then be listing on ebay. I usually sell them for $89.50 with the new module installed. If you'd like, I can post a link when I get one ready this evening if you'd like to take a stab at it. Should be good to go for quite a while with the new IPM installed.

[arronius]

Re: help with nexus nx422 (lg panel #pdp42x30000)

Yeah that'd be great! Might as well try it at that price.

[aaronwt6]

Re: help with nexus nx422 (lg panel #pdp42x30000)

Sorry but no luck with the one I had on hand. I have two others to try to work with but not sure when I'll have time. Will keep you in mind when I get to them if you still need it.

[arronius]

Re: help with nexus nx422 (lg panel #pdp42x30000)

Hi sorry it's been a while. Yes I still need one there are some on eBay right now but I can't tell if I need one with the matching part # printed on the board or the one on the white sticker?

[aaronwt6]

Re: help with nexus nx422 (lg panel #pdp42x30000)

I haven't had any luck getting the remaining ones I have going. There are several different numbers that will work. Basically, look at the pics and if it looks like your board then it should be ok. This is not always the case with many other boards but these are all interchangeable as long as is it for the LG 42x3 series of Plasma Panel. Here is a list I've compiled of at least most of the TVs that use it. There is also an HTC model that I've had but can't remember which one.

AKAI PDP4273M1
AKAI PDP42Z5TA
HAIER 42HP25BAT
HITACHI 42HDF39
HP CPTOH-0602
HP PL4260N
INSIGNIA NS-42PDP
LG 42PC1DA-UB
LG 42PC3D-UD
LG 42PC3D-UE
LG 42PC3DC-UD
LG 42PM1M-UC
LG 42PX5D-EB
LG DU-42PX12X
MAXENT MX-42HPM20 P420142X3
PELCO PMCP642
PHILIPS 42PF9431D/37
PHILIPS BDH4241V/27
SABRE PDT423BKA
SABRE PDT425BKA
SONY FWD-42PX2
TOSHIBA 42HP16
TOSHIBA 42HP66
VIORE PDP42V18HA
VIZIO P42HDTV10A

[arronius]

Re: help with nexus nx422 (lg panel #pdp42x30000)

Hey thanks man ordered one on eBay Monday. I went with one that had the exact same part number just to be safe plus it was a good price anyways. Should be here Thursday I'll keep you posted on the outcome.

[arronius]

Re: help with nexus nx422 (lg panel #pdp42x30000)

Ok so I got the ysus board today and the solid white screen is gone but it still won't display and input or menus. The back light comes on and that's it. I tried swapping between my two control boards and it made no difference. I have 14 days to return the ysus for a refund so if I can't find out how to fix this before then I will be selling the tv for $20... anyone interested? Lol

[aaronwt6]

Re: help with nexus nx422 (lg panel #pdp42x30000)

It's not a backlight on a plasma, but if the screen is glowing then the Y-Sustain board is now working. You may have an additional issue. When you say you tried two main boards, are you referring to the input board or the control (logic) board? That would be the small board located underneath the input board.

Also, are you sure you have all of the cables connected back properly between the logic board and everything else?

[Alastair E]

Re: help with nexus nx422 (lg panel #pdp42x30000)

With the V8 and X3's its been my experience that this fault id the X-SUS IPM, and not the Y-SUS IPM thats gone faulty.

No probs though--they are both the same,--YPPD-J018C

[arronius]

Re: help with nexus nx422 (lg panel #pdp42x30000)

I switched between the two logic boards I have 2 because that is what I originally thought was wrong with the TV. I have also triple checked all of my connection and they seem fine. Also I double checked my va and vs voltages and they're spot on to the specs.

Not quite sure what you mean by xsus i know there's a zsus board but is there a third board I don't know about?

Either way I'll probably be cutting my losses now instead of dumping more money in this damn thing.