LG plasma 60PA6500-UA purple tint, entire screen, at startup

[Poor Flick]

What would cause a purple tint on the entire panel when turning on? When it would happen (not often) the tv would be cooled down as in overnight. All of the image would be there, but everything was in shades of pink/purple. Turning off and re starting after about 5 minutes, it would be fine. THANKS!

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Just to add, I found one guy doing a You Tube video for Shop Jimmy mentioning a z sus possibly causing this. He was showing boards in a tv and what problems they could cause. Anyone else agree? Thanks!

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Any takers on this?

[mmartell]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Yes zsus but the fact that it is intermittent indicates a possible bad solder joint. This may be the common problem with some LG zsus boards, did you do a search for this model ?

[tom66]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Likely Z-sustain, small chance of low Vsus on power board causing this too.

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Sorry for not getting back to you guys, I've got a lot going on lately. I do appreciate your help!

Thank you mmartell,
I looked before I started this thread but I didn't see anything like my problem. After reading your response I searched again, this time about discoloration. It does seem LG needed to work on their soldering robots. Mine has only done this several times, and then only after it was cold, after being off for several hours and only at startup, never while running for a while. Shutting it off for about 5 minutes and restarting would correct it. With #3 reading glasses and in the daylight, I looked at all of my boards front and back, paying attention to solder joints along with any other obvious problems. When I saw any suspect joints I gently rocked the component while looking at the solder joint but didn't see any movement. However I am new to this, I may have mis judged a joint.

Thank you tom66,
if this is a component issue on the z sus, which part, and would it be easily replaced? If the legs are very close together, I would need to work on my soldering skills first. I've also heared of multi layer boards which sounds challenging.
Low v sus? I checked all of the voltages listed on my panel label, I didn't see v sus listed. I do have vs listed, 205v reccomended, and at various areas on boards I do have 205v at the plugs where indicated.
I also have 2 of my fuses with 335v not listed on my label.
Should I run the tv with the back off so next time I can check voltages? (No kids are here)
Maybe use a plastic stick to push on parts on the z sus board?
Would it damage anything to run with a purple tinted screen while testing?
Many thanks to you both!!

[tom66]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Could you supply a photo of the problem?

The boards are single layer, easy enough to replace components on, but if you have never repaired one before yourself it may be hard so it could be better to simply swap the board.

You can run continuously in the purple state with no harm to the panel - I do not know about the electronics but it is probably not going to get any worse than it is already... You can also run with the back cover off and test voltages. Try checking Vzbias on the Z-sustain too.

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Sorry Tom, I should have included that at the very beginning.

[tom66]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Interesting.... Not a Z-sustain fault, that's for sure.

Can you post a picture of the control board? It's the one in the centre of the TV, green in colour, connects to a lot of other parts...

[Alastair E]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Dodgy LVDS cable/plug/socket possibly.....?

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

I think this is it, is the LVDS cable the silver one? The terminals and plug pins looked clean. I didn't think to check if they were seated completely before removing for inspecting earlier. All ribbon connectors were removed and inspected without checking to be fully inserted first. I still have my training wheels on! If I need to generate the test pattern, I'll have to get back with you guys a bit later, I'll be away from home for a while. I had these pictures on my phone. Thank you guys!

[Alastair E]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

The LVDS will be the cable that goes from the Mainboard,--one that has all the input sockets on etc, and that control-board....

Carefully remove the cable, wipe over the contact area of the cable with some contact-cleaner/WD/40 on tissue then refit--Do Both ends.....

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Ok Alastair, I'll actually go back over all the ribbons as I think the WD-40 would be a good idea to prevent corrosion. Would it be a good idea to spray it into the ribbon sockets on the boards also? I can hold some paper towels around the plugs to avoid other areas.

[Alastair E]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

No, no need to fill the sockets with the stuff--just a little on some tissue, wipe over is fine....

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Ok, Thank You!

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

BTW, I don't like having leftover parts, and I did search for threads on this with no luck so I'll just go ahead and tell on myself here. During my removing and inspecting of the boards, I have forgotten where a couple of these soft rubber blocks came from. I don't have a picture as I'm away from home for now. I should have left them stuck to my panel, another rookie blunder. Is it possible they help dissipate heat? Maybe they go beneath heat sinks? They did come from under the boards somewhere. I haven't ran it yet.
Thank You!

[tom66]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Usually they leave a bit of adhesive mark where they were...

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Yes Tom, we call that witness marks in my line of work, I've used that visual evidence many times working on school busses. I have no idea why I cleaned my panel and boards without note taking, marking or picture taking. That practice is common at our shop. So, now that I'm done, hopefully, painting myself into a corner, is it a fair guess they go under the heat sinks or would that be the opposite and be a heat insulator? When I get back home maybe see if my other boards still have any in place. It's been quite a while since I've worked on it and my memory isn't sharp anymore. Thank You!

[tom66]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

They usually go underneath exposed connections, or transistors on the sustain boards.

[Poor Flick]

Re: LG plasma 60PA6500-UA purple tint, entire screen, at startup

Ok, once again many thanks, Tom!