idh@NABLA.ELECTRICAL-ENGINEERING.UMIST.AC.UK (Ian D Hawkins) (05/03/90)
My thanks to those who replied to my posting on the subject of dimming SM124 white characters on black background; It appears lots of people have had this problem but no one knows the solution. Suprisingly, Atari UK claim to know nothing of this 'feature' of their monitor. The phenomenon seems limited to 'heavy' SM124 models that use a large mains transformer, later versions using a light switched mode PSU are not affected, neither are SM125 monitors. A service man (Charles) fom Silica shop seemed more helpful, and said he would investigate the problem if he could reproduce it on his SM124. Since the Germans seem to be the best ST hardware hackers around perhaps a German reader of this BBS may have read of this and be able to shed light on the topic.
ripley@tubopal.UUCP (Ch. Eckert) (05/09/90)
]In article <9004271625.a015851@nabla.electrical-engineering.umist.ac.uk> idh@NABLA.ELECTRICAL-ENGINEERING.UMIST.AC.UK (Ian D Hawkins) writes:
]When I use my SM124 monitor with inverse video (white on black)
]I find that the characters become increasingly dim, eventually
]becoming illegible; most especially when the screen is almost
]entirely black already. Has anyone else found this/got a
]solution ?.
I have it, too.
The solution is quite simple. You only need a 20k-potentiometer and solder
it parallel to a condensator. As I don't have the curcuit-map of the monitor
handy at the moment, I can't tell you which one it was, though.
This patch was sent to me by Volker Brandt from Bonn (vbrandt@dbnuama1.bitnet,
I don't know if he still has this account, I only remember dimly there
changed something). Volker, if you are still around, can you tell which
condensator it was?
Greetings,
RIPLEY
Disclaimer: I still haven't installed this (sigh). I can't guarantee, that
it works.
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