eem@DSPVAX.MIT.EDU (Evangelos Milios) (03/04/86)
I had an unpleasant experience with two Atari 520 STs
(the standard monochrome configuration), I received through
mail order. The first one I got showed a screwy display a few minutes
after I turned it on for the first time. I sent it back the next day
for exchange. 10 days later I received another one, whose display develops
a slight blurr about 5 minutes after turning it on. About 5 minutes later,
the blurr goes away, and the picture stays normal for the rest of the
session. The same thing happens with remarkable regularity (plus/minus
one minute - I timed it) every single time I turn it on after being off
for several hours. Recycling the power of either the computer or the
monitor after the first 10 minutes does not spoil the image.
Has anybody seen this problem before? Atari hasn't.
Any fixes? Please answer fast, I only have a 10-day exchange period.
...Evangelos
-- MIT Digital Signal Processing Group
UUCP: {seismo,pur-ee}!mit-bug!eem
ARPA: eem@mit-bugs-bunny.arpaadam@TTIDCB.UUCP (03/08/86)
(Does something still eat this line? Rn doesn't.) It sounds like either a thermal problem in the high voltage focus (is the de-focus all over the crt screen) or posibally (but less likely) a thermal problem in the crt gun structure itself. The only way to determine if I'm right would be to disassemble the monitor and play with the focus pot while it is warming up, or use cold spray on it after it is warm. It is not likely to get better but may stay that way for years. If you can do without it for a while, send it back. You payed to have it perfect! Mine is OK but note that since it works at 70 Hertz, and everything around it is 60 Hertz, it is very subseptible to magnetic field interaction. You will know when the picture starts moving or waving at you. I can't have the color monitor on (but unused) and next to the B/W (12 inches) while I am using the B/W. Also, keep the power blocks (transformers) away from the monitor -- especially the back. Move them around the monitor with it on to see what I mean. Good luck. Ken Adam
uh@unido.UUCP (03/09/86)
We had also some trouble in this direction. We have bougth about 30 ST's
and two of them have had the same fault(s). Our dealer told us, that this error
always occurs, when the custom MMU is defective. The same thing I have read
in a ST magazine here in Germany.
Uwe Hoch
Computer Science Department, University of Dortmund
4600 Dortmund 50, P.O. Box 500500, W.-Germany
E-mail address: uh@unido.uucp, uh@unido.bitnet