Wednesday, April 21, 2010

LG Plasma TV Red Snow

If you have a TV that does something similar to this image, you might be able to fix it yourself with just a screwdriver. This is sometimes just red, sometimes just green, and other times mixed like in the picture. My tv was covered in red pixels up to 80% of the screen. It started out as just some red dots in the most dark areas, but it increased up to the point when I decided to either fix it, or kill it, so I can get Wife Acceptancy for a LED TV. Well, it so happens that I fixed it without knowing what I was doing, but using my brain.



What you need first is to get the following gear before you start unscrewing anything:
  1. a flat screwdriver with a 2-3mm head, preferably isolated handle, you can isolate it yourself with some plastic or rubber
  2. a rubber dish washing glove so you don't kill yourself if the screwdriver makes contact with anything electrified
  3. a clear dinner table
  4. a stack of books
  5. a mirror sized so you can slide it under the TV
  6. a DVD-player running a movie, connected to the tv on the AV1 channel
  7. an electric screwdriver, there are a lot of screws
  8. fine point permanent marker
Then you remove the back panel, by removing all the screws except those under the connectors in my case, that panel is separate. In my case you need to remove the "legs" to remove a couple of the screws. Get some books, put them on the dinner table in 4 equal stacks, and put the TV with the glass down on the books. Slide the mirror half way under the tv. Get the back panel off, and it should look like this:
You will be working in the areas marked 1 and 2. Locate anything you can screw on, with a Philips adjustment head. Sometimes orange, mine were grey. You're trying to locate one called VSCAN, that should be marked on the circuit board, just besides the adjustment head. Mine was of course called Vs, so I assumed (correctly) that I had found it. Mark the adjustment head position with a fine point permanent marker so you can go back to the exact original setting.


Put the screwdriver in the adjustment head, start the TV in HDMI mode and start looking in the mirror to see if the adjustments make any difference. Turn first left, and if left gives more bad dots, turn in the other direction. You should get less of the red dots in the left direction. I turned mine to maximum counter clockwise.
The adjustment head just besides the marked area is some 5-volt adjustment which on my TV does nothing, but if I turn it too much, the TV shuts down, probably as a failsafe against too high voltage.

If you try and adjust this, and the TV shuts down, Don't panic, just disconnect the TV from the outlet, and wait a minute. Also turn the
adjustment head back to the original position.
Move on to the next circuit board, where you find more adjustments. Mine shows SETUP, SETDN, and a third unmarked. I tried all of them, and all of them correct the red pixel phenomenon to some extent. The SETUP and SETDN are on my TV now one turned to the limit clockwise, and the other one counter clockwise, since those settings gave the best picture. The last unmarked adjustment head did get rid of the last of the red pixels. There was a last grey adjustment head which I didn't tamper with since I was happy with the results. Try these settings on the AV1 channel with a DVD running, so you don't adjust only for HDMI. Shut down the tv for a couple of minutes, start up, and check both channels again, to make any last adjustments.
PLEASE, DO THIS WITH EXTREME CARE SO YOU DON'T GET ELECTROCUTED. WEAR RUBBER GLOVE AND RUBBER SOLED SHOES. DON'T SPILL BEER IN THE TV AND TRY TO WIPE IT CLEAN DURING OPERATION!

Shut down everything, and put it back together.
Good luck!

25 comments:

ashish sood said...

how does it look after you applied your fix?

Adrian said...

almost no "snow" but some dark spots appear when warm in the left down corner. Maybe I just turned the knobs a bit too much

Adrian said...

You'll have to do the tuning with the TV on higher book stacks, and have several mirrors, so you can see what's happening when you're turning the knobs. A bright picture on the screen is recommended, I had black only,

7dayhandyman said...

Excellent work buddy. Thanks. and Beautifull blog. You can also distributes your ideas and experience sharing on Plasma TV Install | Plasma TV Installation | Plasma Installation

Adrian said...

Thanks 7dayhandyman , feel free to link to my posts.
My latest on TV-s is on the latest Samsung 6-series.
/adrian

troy said...

Can't thank you enough. At first half of my tv was out. Then all of it except for about 3 pixels. So I figured I had nothing to lose by trying this. Glad I did. With some adjusting of all the adjusters I was able to fine tune my tv back to full life. Again thank you!

Adrian said...

Actually, knowing my work helped ONE other person feels really good. Thanks for posting!

rosiebuddy said...
This comment has been removed by the author.
rosiebuddy said...

Wow!! You saved my TV. I was going to junk my 2 and a half year old LG 50" 50PS70. I had a guy out for service and he quoted me about 365.00 to replace the YSUS board. I said "No". Instead I tweaked it back to life using your tips. Any idea on how long this might last? Constant tweaking of the boards? I'm sure something is going. I just want to get the most out of it. Thanks again

Adrian said...

Well my tv got slightly worse over time, but still better than without the tweaks. It'll work untill you decide to buy a new one ;)

Glad I could help!

The Williams family said...
This comment has been removed by the author.
The Williams family said...

It's been a couple of years now. I'm curious, how long did it last?

Adrian said...

It lasted a couple of months, until our house was burglarized and the thieves stole it. It got slightly worse, but not as bad as before the fix.

Ashley Clamp said...

i've got the picture i want but every half an hour or so my tv shuts down and i have to take the power cable out wait a minute and i put it back in and it works.... HELP?

Adrian said...

It's probably the voltage being turned up too much. Turn it back down one notch at a time until it stops shutting down. It happened to me too, and I I too had to settle for a less clean picture but a tv which doesn't shut down all the time.

Adrian said...

Read the instructions again, especially the voltage knob part.

Linkeboa said...

Great work! I tuned the screen with black only. Didn't have a mirror so I had to walk a lot. Still a few dots on black screen but other than that the image is perfect now.

Сергей Батюк said...

Спасибо за подсказку. Я отрегулировал и всё получилось.Красные большие пятна пропали. Но на светлом фоне появляются вертикальные красные полосы но их меньше чем было красных пятен.

Adrian said...

http://www.ebay.com/bhp/lg-ysus-board

20$ for a new ysus board. Should be easy to replace, like a couple of screws and a connector. That should hold for at least 2 years.

Сергей Батюк said...

Спасибо

Adrian said...

пожалуйста

Adrian South said...

Thank you Adrian!!
We were just about to throw our 50" plasma away because of this fault.
An hour or so later and your solution has fixed the snow problem.
Like you I had to completely turn one pot all the way anti clockwise.

Many, many thanks once again
Adrian (London)

Adrian said...

Glad to hear this works even many many years later :) Of course, check out the comments above where I mention buying a replacement YSUS board

Unknown said...

Hey bro, after you do power supply VS and VA is it imortant enough as in the other tuners can blow the ic's or maybe that just happened cause it was going to happen? What are the ones on the Zsus used for on the pretrusing daughter board? Also the three on the Ysus are setup, setdp and the third? I am doing it now. I do have pink lines from no screen after new zsus now I blew a buffer and don't think it took my Ysus with it so I will be doing this all soon while waiting on new buffer board for PL4260N tv. Thanks. -Stephen

Stephen Regan said...

Can I set VA and VS whilst waiting for the boards or do the boards need to be in to PULL the current to test for VS and VA and also do you know if counter or clockwise is less or more current? I think I blew my ic's by doing that as in turning it blindly like a idiot but the ones on Ysus and zsus one can turn without any issues except a screen as in it won't blow anything usually?