#C=1950MonitorHelp
6 messages in this thread
I bought a Commodore 1950 multiscan monitor with my A3000 several years ago.
Now it has developed an intermitent problem, which seems to go away after it
has warmed up well during work sessions. What happens is that suddenly the
screen will go very dark gray with somewhat jagged edges to the windows. The
WorkBench image is still visible, but so distorted that text is unreadable.
The WB image is doubled also. Sometimes it just "pops" back to normal on its
own, sometimes if I drag with the left mouse button at the top of the window,
it will pop back to normal, or, thirdly, sometimes just turning it off for a
few seconds will correct the problem. I'd like to know whether anyone else has
had this problem and was able to run down the cause. Is there anyone who has
schematics for this monitor, or knows where I could obtain a set to take to my
repairman? Does anyone know someplace I could contact to have it fixed? Thanks
for any help. George
George,
It sounds like the monitor is having trouble with H sync. If the 1950 is a
little late in detecting H sync, it will clamp (that is, zero out the video
circuitry) on active video instead of black. (Black is at zero volts,
relatively speaking.) When the monitor clamps on video, it sets the reference
level too high, which makes the rest of your video too dark.
You need to check your cabling; it's the easiest thing to look at, anyway.
Check for good connections at each end, with no loose pins. It would not hurt
to shake the cabling, gently, while running Workbench. If your image snaps in
and out, you've got an intermittent connection.
Otherwise, you'll need a tech to look into the H and V sync circuitry of your
1950. You might also want to verify that your Amiga isn't putting out a weak
sync signal. Can you borrow another multi-sync (not a 1084) to check this out?
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Thanks Bruce, I'll pay some attention to the cable. Know any sources for
schematics? G Roland
I don't know monitor electronics real well, but that problem sounds
obvious enough that even if the guy you took it to didn't have the
schematics and he was willing to try a few things, without charging you an
arm and a leg (that is, if he's a friend or trusted acquantance) he could
probably run down the problem.
Robb
(being culturally conscious, all above 'he's are not gender specific)
Thanks Robert. My repair guy looked the thing over, firmed up a few
questionable solder joints, which seemed to stop the problem for awhile, but
now it's back. Any ideas about schematics? G. Roland
It still seems to me that someone who knows monitors ought to be able to
find the problem, but keep my CI$ address on file. There's a place near me
that fixes C= (and other stuff) and they're still even doing c64 repair. I
drop by there a couple times a month to see what's up. Since they mostly
are a repair shop I don't go in to buy anything real recent. They may have
some line on docs for the 1950. They've been real helpful to me, but I'll
probably space it, the commute home can be a pain. The point is I've
printed off your description, I intend to go to this guy and ask him about
it, but if you don't at least hear a 'nope' from me in the next few days,
send me a reminder.
Robb