Need help with monitor in Japan

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Wed Jul 14 17:42:56 2004

>
> Hi All.
>
> I'm in Japan and having a problem with a US monitor.
> It won't turn on...no power light or power up noises
> or anything.
>
> So I measured voltage across neutral and ground and
> there was 8VAC. So I got an electrician to wire up a
> proper ground. There's still 1VAC across Neutral and
> Ground.

This should not be a problem. No device should ever assume that either
side of the mains is close to earth potential (because in some cases it
won't be). US wiring is uncovnentioal in that the neutral and earth are
connected at the house's fuse/breaker box, this is not the case in other
countries.

>
> So I have two theories:
>
> 1) The monitor is seeing the floating ground and not
> liking it and refusing to turn on.

I can see no reason why it would object!

> 2) The monitor requires at least 110V (I'm getting
> 103V).

Possibly, but fairly unlikely. A PSU should be able to take +/-10% from
the nominal mains input. Which would mean it should take 115-11.5V
(103.5V). You'd be very unlucky for it to object to 103V.

>
> I'd hate to think this thing just died, so can anyone

I assume you've checked the fuses (including the internal one in the PSU
area). Have you done any other internal tests?

My guess is that the startup resistor has gone open. It happens. Look for
a resistor (maybe 2 in series) of a few hundred k from the +ve side of
the maisn smoothing cap to some point in the choper circuit.

-tony
Received on Wed Jul 14 2004 - 17:42:56 BST