Plasma HDTV failure (no video)?

[Stealth3si]

My 2 year old LG plasma 60PS11 TV has no video but has sound and the menu button doesn't show the OSD on the screen. CS says either the panel or the circuit boards behind the TV need to be replaced.

I was the last one to use it and while I was waiting for a video file to load from a media box, I left the TV screen on for a few minutes too long, with no video or audio signal. And I think those are what caused the problem but I could be wrong.

What would cause a panel or circuitry board to no longer function?

[yoda313]

Have you replaced the hdmi cable on this set? Is it loose? I'd check that before jumping to conclusions.

Or are you using an hdmi switcher? Maybe the switcher is going bad?

[mrswla]

Also try unplugging the tv power cord from the wall for a minute and see if it resets.

[Stealth3si]

yoda, the menu button doesn't seem to "work" from the TV. No OSD at all, which should be displayed even without video connections, right?

mrswla, I did that too.

[Stealth3si]

After some thought, is there a solid basis to make the claim that a media box can do this?

Now I'm not looking to blame others because I was the last to use it and more than likely I probably did something unknowingly to mess it up, but I am looking to find out whether or not the cause of the damage to the TV is internal or external or both.

[jagabo]

I probably did something unknowingly to mess it up

No, the TV probably just happened to die and it had nothing to do with what you were doing.

On the off chance that it just crashed, try what mrswla suggested. Unplug the TV's power cord and let it sit overnight (a hard reset). If it still doesn't work in the morning its dead.

[yoda313]

the menu button doesn't seem to "work" from the TV. No OSD at all, which should be displayed even without video connections, right?

That would seem logical. I was just trying to offer advice for the basic diagnostic approach.

[Stealth3si]

Yea it's dead jagabo.

[jagabo]

If you're lucky it might just be bad capacitors in the power supply. That's a very common problem with many HDTVs (and other electronics). You can replace those for a few dollars if you're handy with a soldering iron.

http://en.wikipedia.org/wiki/Capacitor_plague

[Stealth3si]

If you're lucky it might just be bad capacitors in the power supply. That's a very common problem with many HDTVs (and other electronics). You can replace those for a few dollars if you're handy with a soldering iron.

http://en.wikipedia.org/wiki/Capacitor_plague

If a bad capacitor stops the TV from powering on or producing sound, then I was wrong when I said it was dead because I still have power and audio, there's just no video signal coming from the TV itself, not even the OSD menu from the 'menu' button on the TV, if you didn't catch that earlier. Would that change your answer?

I want you to know that I had an LG tech look at it who said the panel is fine but the cost to fix the real problem may be somewhere around the $600 range even tho he did not give me an exact estimate. He also couldn't tell me which specific parts were bad or the precise cause of my particular issue without charging a $76 diagnostic fee, which I think includes the total estimate for labor and parts. So I asked him to come back later this week to see if they could arrange a concession for a free diagnostic, mainly because the tech person on the phone told me the other day it was free!

Anyway, I asked him some questions related to his professional experience and technical knowledge. I.e., he does 7 jobs a day and whatever the actual problem and cause I'm having with my TV (which he did not mention) isn't unusual for plasmas because they have had many thru the years that needed similar repairs because of their high wattage, unlike LCDs.

However, IIRC, he mentioned it's also rare for this to happen. Technically speaking then, how did this happen? Would it happen again? Should I fix it or scrap it and get an LCD instead?

So then, according to him, most likely the common causes of these things has to do more with something inside the TV. What specific parts? I have no clue, except for the capacitor you mentioned.

[jagabo]

There are low and high voltage power supplies in the TV. The low voltage section supplies the electronics. The high power section drives the plasma display. Bad caps in the high voltage section would explain why you have sound but no picture.

[Megahurts]

If you had an LCD TV then I would say 90% of the time that it's a capacitor problem. A capacitor problem in a plasma is very rare if non existant.

If there is audio then the most comon problem with plasmas is the sustain board which is fused. If one of the fuses is blown then the sustain board is bad. If no bad fuses then suspect the buffer board. A bad display panel could cause the buffer board to fail.

For a plasma, it's best be left to a professional.