Jeffrey Delzer <[log in to unmask]> wrote:
> I have an Idek Iiyama MF-5015A 15" monitor that's been in continuos
> service since I got it in 1992, and the brightness has dimmed
> considerably over the years. Long ago I reached the point where the
> front panel Brightness control was maxed out, but a few weeks ago I
> decided even that wasn't enough, so I opened it up and tweaked up the HV
> pot as far as it would go. It was only about 1/16 to 1/8 turn from Max
> already, so it wasn't a big increase, but the display is noticeably
> brighter now, although still quite a bit dimmer than the other monitors
> I have here.
>
> My question is, are there any safety concerns related to increasing the
> High Voltage like this? It's been 2 weeks and the monitor isn't
> complaining in any obvious way, but I've had non-stop headaches since
> then. Is this thing throwing X-rays at me now or anything? :)
>

DANGER, DANGER!

YES! Increasing the HV beyond its rating will increase X-Ray emission. The usual
method for adding a little more life to an old CRT is to increase the filament
voltage. They used to make little transformers specifically for this purpose in
the old days for TV's, but there probably isn't much market anymore. In
addition, the source of the filament voltage is such that it may not be easy to
increase.

I would recommend that you just get a new monitor. You could have the CRT tube
replaced, but that is usually more expensive than a brand new monitor.


--
Russ Poffenberger               Engineering Specialist
Schlumberger Technologies ATE   DOMAIN: [log in to unmask]
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