I just purchased an old Commodore 1902 monitor (analog RGB/digital RGBi
15Khz built in 1985) to replace a similar Commodore 1084D monitor. The
previous owner had it in storage for some time. The monitor will turn itself
off (apears to look just as though I physically turned it off...but power
light above switch will wimper a few times before going out) after about 5
mins from a cold start, and about 3 mins after a warm start. As soon as it
turns itself off, I can turn it off and on again right away and works for
another 3 mins or so.

One thing I noticed about the display (as soon as I turned it on for the
first time upon purchase) was that the sceen was quite intense as though the
contrast was to high (not brightness control). Turning the contrast control
all the way down was almost normal but even still to high....not sure if
they are related....

My electronic abilities/skill only afford the ability to seek out bad
electrolytic caps, measure resitor values and check diodes....before I crack
the case and look for obvious signs I just wondered if someone has
experienced this before (I imagine it is a common problem for monitors of
this age) and could point me in the right direction.

Please respond to the newsgroup and my email. Thanks! jerry

First do an ESR test on all the caps in the monitor, especially in the scans
and power supply. It is very likely you will have to change many of them to
start with.

--

Jerry G.
=====

"Jerry Lynds" wrote in message
news:6iCEd.62149$nN6.35688@edtnps84...
I just purchased an old Commodore 1902 monitor (analog RGB/digital RGBi
15Khz built in 1985) to replace a similar Commodore 1084D monitor. The
previous owner had it in storage for some time. The monitor will turn itself
off (apears to look just as though I physically turned it off...but power
light above switch will wimper a few times before going out) after about 5
mins from a cold start, and about 3 mins after a warm start. As soon as it
turns itself off, I can turn it off and on again right away and works for
another 3 mins or so.

One thing I noticed about the display (as soon as I turned it on for the
first time upon purchase) was that the sceen was quite intense as though the
contrast was to high (not brightness control). Turning the contrast control
all the way down was almost normal but even still to high....not sure if
they are related....

My electronic abilities/skill only afford the ability to seek out bad
electrolytic caps, measure resitor values and check diodes....before I crack
the case and look for obvious signs I just wondered if someone has
experienced this before (I imagine it is a common problem for monitors of
this age) and could point me in the right direction.

Please respond to the newsgroup and my email. Thanks! jerry

"Jerry Lynds" ) writes:
I just purchased an old Commodore 1902 monitor (analog RGB/digital RGBi
15Khz built in 1985) to replace a similar Commodore 1084D monitor. The
previous owner had it in storage for some time. The monitor will turn itself
off (apears to look just as though I physically turned it off...but power
light above switch will wimper a few times before going out) after about 5
mins from a cold start, and about 3 mins after a warm start. As soon as it
turns itself off, I can turn it off and on again right away and works for
another 3 mins or so.

I have no idea, but I've got two 1084's that have bad switches. One I got
with the bad switch, the other went bad after a few years of use (both
came to me used). The second one, it had the same sort of symptoms,
in that on/off was flakey for a while and then it finally failed.

The button on the 1084's is mechanically coupled to the actual switch,
and from when I took it apart, I think the coupling fails. It's been
a few years since I looked at it. Before I took it apart, it would stay
on, but I had to hold the switch in.

I had a third monitor to put to use, so I put the old one away. I was
planning to replace the switch, and mount it at the back, but never
got around to it.

I gather this is a known problem with the monitors.

So I'd suspect something this simple at first, though given that it
may not be so easy to get the mechanical parts to fix it, it may be
a troublesome repair.

Michael

One thing I noticed about the display (as soon as I turned it on for the
first time upon purchase) was that the sceen was quite intense as though the
contrast was to high (not brightness control). Turning the contrast control
all the way down was almost normal but even still to high....not sure if
they are related....

My electronic abilities/skill only afford the ability to seek out bad
electrolytic caps, measure resitor values and check diodes....before I crack
the case and look for obvious signs I just wondered if someone has
experienced this before (I imagine it is a common problem for monitors of
this age) and could point me in the right direction.

Please respond to the newsgroup and my email. Thanks! jerry

Jerry -
I bought one of these at a flea market for $10. Mine did the same thing - or
acted very similar.
I took it to the TV repairman and it ran fine for 12 hours in his shop
(uneven surface must have warped the board 'just enough?'). So I took it
home and once again, wouldn't work. I popped the cover and inspected.
This was long ago, so I barely remember if there is an RF shield plate
covering it that had to be (re)moved...

Check the solder joints on the large power transformer leads and ground
points at the circuit board - they are notorious for cold and broken joints
(if I remember the OLD posts from 1990). I resoldered all the cold joints
and it ran fine ever since.


"Jerry Lynds" wrote in message
news:6iCEd.62149$nN6.35688@edtnps84...
I just purchased an old Commodore 1902 monitor (analog RGB/digital RGBi
15Khz built in 1985) to replace a similar Commodore 1084D monitor. The
previous owner had it in storage for some time. The monitor will turn
itself
off (apears to look just as though I physically turned it off...but power
light above switch will wimper a few times before going out) after about 5
mins from a cold start, and about 3 mins after a warm start. As soon as
it
turns itself off, I can turn it off and on again right away and works for
another 3 mins or so.

One thing I noticed about the display (as soon as I turned it on for the
first time upon purchase) was that the sceen was quite intense as though
the
contrast was to high (not brightness control). Turning the contrast
control
all the way down was almost normal but even still to high....not sure if
they are related....

My electronic abilities/skill only afford the ability to seek out bad
electrolytic caps, measure resitor values and check diodes....before I
crack
the case and look for obvious signs I just wondered if someone has
experienced this before (I imagine it is a common problem for monitors of
this age) and could point me in the right direction.

Please respond to the newsgroup and my email. Thanks! jerry