Date   : Wed, 07 Dec 2005 14:10:20 +0000
From   : Richard Gellman <splodge@...>
Subject: Re: Repairing Taxan Super Vision 625 VDU

Raf wrote:

> I have one of these monitors and recently the normal
> text colour of white has progressively changed to yellow and more 
> recently to green. Graphics are correspondingly "miss-coloured". Can 
> anyone help, please?
>
> Thanks
> Raf

White is composed of all three of Red, Green, and Blue signals. Changing 
to yellow indicates a failure of the Blue component (Yellow is made of 
Red and Green), and thusly changing from there to green indicates a 
failure f the Red component.

I'm guessing Red, Blue and Magenta don't appear at all, and Cyan, Yellow 
and White appear Green.

While I can offer no advice in repairing it, I can give you afew 
suggestions on possibilities:

Failure in the signal cable - not that likely as this would be an 
instant chage rather than gradual, but worth checking.
Gun failure of Red and Blue guns. This is apparently quite a common 
occurence with Taxan monitors (remembering a Micro User letters page 
entry mentioning the same). In this case, reparing will be hostile.
Circuit failure on Red and Blue signals. Monitors have signal processing 
circuitry for each of the signals (for most this is as simple as 
amplification/cleanup) - This could have failed for Red and Blue, again 
difficult to repair.

Unfortunately, unless its something simple like a loose wire, the 
chances of repairing are looking slim.

Since the Red and Blue lines seem to have both gone in the same way, you 
might expect the Green line to go soon too, leaving you with a glorified 
black box.

-- Richard