Dying monitor

Is that the old 19" monitor with the damper wire shadows in the middle? I'd just use it until it blows. Then it would be obvious what was wrong. I've sold tons of Dell Trintrons back in early 2000s and don't recall a common problem. Hell I don't even recal A problem. Besides if your monitor is over 5 years old it surely isn't suffering from common problems is it? A heat related shut down could be a lot of things. My 53" Panasonic TV will turn itself off and then right back on usually once an evening. Am I woried about it? No. How do you track something like that down? Good luck.

Local Goodwill stores have many CRT flat screen monitors, usually around $20, you might find a replacement there. I've seen Sony Trinitrons there and in fact took some there myself.

My guess is the CRT is drawing more current as it ages. Eventually it reaches the point that the X-ray protection circuitry shuts it down. The protection circuitry might also be degrading with age so that it's more sensitive than it should be. You could try turning down the brightness. Fixing it probably isn't economic unless you can find another one just like it but with a different problem that you can use for parts.

Is it CLEAN inside? I once found the flyback transistor getting leaky, getting hot. But, was accompanied by distortion so was the obvious area to look.

The 'few minutes' of turnoff would be consistent with cooling some temperature-sensitive component.

The 'many years' of work might mean that a blanket of dust and cat hair has settled on the innards; it might be that all this machine needs is a good vacuuming with the back cover removed. Disturb not the anode wire unless you know how to discharge it safely!

On 10/24/2009 11:41 PM David Nebenzahl spake thus:

Thanks to all who answered. Sorry, but I described the failure mode incorrectly: what happens is that the screen suddenly goes black, with a bright flash in the center, but no relay clicks. If I try cycling the power immediately afterwards, the green power LED comes on briefly, then goes out, again with no relay clicking.

I think I'll open 'er up and see if there's a dust buildup. Other than this the monitor still performs perfectly.

On 10/25/2009 11:50 AM David Nebenzahl spake thus:

To follow up on my own posts, I went ahead and opened 'er up. As you can imagine, it was quite dusty inside, so I got out what I could with my airbrush compressor blowing and a vacuum cleaner wand sucking. Couldn't see any obvious problems, so I put 'er back together. She's working fine so far (knock on a forest product), but it's too early to tell.

Yeah, that's what I'd start with. I'd bet that there's layers of crud all over everything & making things overheat.