CRT decay - test-drb@ccmp.vtda.org

3 Nov 1998

-----Original Message-----
From: Tony Duell &lt;ard(a)p850ug1.demon.co.uk&gt;
To: Discussion re-collecting of classic computers
&lt;classiccmp(a)u.washington.edu&gt;
Date: Wednesday, 4 November 1998 14:50
Subject: Re: CRT decay
...
   On this
subject, but perhaps not quite on topic, I have a VGA monitor
 which performs perfectly well if it is left on all of the time but if it
 is switched off for more than an hour or so then it takes time for the
 picture to reappear.  Strangely it seems that the longer it is switched
 off the longer it takes to 'warm up', in the extreme case after bieng off
 for a week or so it can take half an hour or so for the pidcture to
 reappear and the brightnedd will fluctuate for some time after that.  Has
 anyone got any idea what is happening? 

At a guess the first anode voltage (second grid for those across the
Pond) is fluctuating. That'll affect the brightness but not much else. 

Have a look for a low value, high voltage electrolytic capacitor in the
vicinity of
the G2 supply.  Possibly even on the neckboard of the tube.  Change it.
Sanyo TV's (others too, but Sanyos seem especially prone) exhibit this
problem also.

Cheers

Geoff Roberts
Computer Systems Manager
Saint Marks College
Port Pirie  South Australia.
My ICQ# is 1970476
Ph. 61-411-623-978 (Mobile)
      61-8-8633-0619 (Home)
      61-8-8633-8834 (Work-Direct)
      61-8-8633-0104 (Fax)