I was helping someone out with an old Pioneer Elite plasma (is that the Kuro line), and an issue came up. When I hit the power button on the remote, the screen would go black and the status light at the bottom left corner would change from green to red. However, I could definitely see the backlight of the display. From what I could gather from the documentation, that meant it was in standby mode. I assume that this is to shorten/eliminate the warm-up time for the set. What puzzles me is that it seems that this is the only state the TV will go into. I couldn't see any way to put it into a full "power off" mode without cutting the power.

This TV has a breakout box that handles all the inputs. Both the TV and the box have power buttons, but it seems like neither of them fully turn off the backlight. Is this weird or is this expected behavior?

Hang on -- surely if you can see the backlight, it isn't a plasma. Plasma TVs have emissive pixels.

Peter

My guess is that if the TV were left alone for a long time in Standby mode, it might eventually fully turn off.

I could be wrong. Maybe that model of plasma display uses so little electricity when pre-charging its pixels, that they considered it to be within acceptable standby-mode power drain specifications, and called it good.

My Panasonic plasma certainly doesn't do anything like that. When it is in standby it is dark.

I've never heard of anyone saying plasmas do that and I have a few friends with those Pioneers.

Weird. And Peter, I'm just describing it as a backlight. All I know is that it's a black screen but with a very slight illumination like the set is still on but displaying no image.

I wasn't there long enough, but it is possible that it eventually powers off. I'll ask about that.

This is consistent with the description in the Wikipedia article, saying that some plasma TVs show this issue and some do not.



Possible explanations:
- It exists on your friends' Pioneer displays, but your friends have not noticed it because the issue is subtle.
- Your friends have newer models which don't exhibit the issue.

The friends I'm thinking of have old style Pioneers and they are the sort of people who would notice

I'm not saying that this warm up standby thing isn't a think, I've just never heard of it. That Wikipedia article seems a little vague and I can't see mention of this issue elsewhere on the net. You'd think it would be talked about somewhere else.

Yeah, now that I've done some more Googling, I think you're right. Here's a forum thread from AVForums where a user of a different model of set did the following:

- Noticed the faint glow in standby mode.
- Confirmed that the glow went away when he yanked the cord.
- Went back to the store and traded in the set for another of the same model.
- With the new set, the problem was gone.

My new opinion of the problem described in the original post:

DEFECTIVE TV SET, REPLACE.

Yeah no backlight in plasma but even the best ones will emit some light when displaying a completely black image. You'll have to have the room dark to see it. But that's fully on and running - just displaying a black screen.

I've never heard of plasmas "glowing" when in standby. They generally don't need any kind of warm up phase either so having it on like that is unlikely to be necessary.

If you / they have a power meter, put it on the set and see. Does yanking the plug kill the glow? If so I'd say it's faulty like Tony, albeit a fairly weird kind of fault i.e. the brains aren't turning the display off.

Lastly I don't believe there's any kind of lingering illumination on any plasma that I've seen. Pulling the cable will verify that pretty quickly.

My experience is from a Panasonic and a Samsung plasma.

Thanks for the input, folks.

It's possible the set is just going bad. She had me take a look at it because she had just removed her cable box and returned it, and now everything was unplugged and she wanted to attach an Apple TV. I hooked everything back up but now it exhibits this behavior. She doesn't think it was like that before.

I wouldn't be surprised if the TV is failing. It's pretty old at this point.