Repair for a "Tunnelling" KDS Monitor?

[Blarneystone]

Hi all,

I have a 19" KDS monitor where suddenly the horizontal size keeps fading
inward. When I hit the side of the monitor, it goes back out to full
screen. But then shortly afterward, it starts fading inward again.

Is there anything simple I can do to fix this problem or is it new monitor
time?

 

[William R. Walsh]

Hi!

If slapping cures the problem, you almost certainly have a problem with bad
solder. A repair with a decent soldering iron and fairly keen eyes shouldn't
be too hard.

But be warned--monitors contain line connected circuitry that is very
dangerous. There is also a hazardous amount of high voltage stored in the
area of the flyback transformer (large black assembly with a line running to
the side of the CRT that looks like a "suction cup") and the tube itself. Be
careful of this--a painful charge is stored for a long time!

If you do not know what you are doing, it would be wise to seek professional
assistance if you want the monitor repaired.

William

 

[exray]

Hi all,

I have a 19" KDS monitor where suddenly the horizontal size keeps
fading inward. When I hit the side of the monitor, it goes back out to
full screen. But then shortly afterward, it starts fading inward again.

Is there anything simple I can do to fix this problem or is it new
monitor time?

I had a 17" KDS that started doing the same thing. I found a TO-220
transistor/regulator that had been overheating and it had basically
unsoldered itself from the board. I pulled it out and it seemed to test
bad so I ordered a new one. I continued to use the monitor in the
'wide' mode and that killed something else before the replacement arrived.
Its probably worth a look to see if it is something this simple. The
transistor in mine was completely loose on the board. Had I caught it
sooner maybe I could have saved the thing but it had some other
unrelated intermittent problems so I wasn't too torn up to see it go.
It misbehaved right out of the box and I've been slapping it on the side
for 5 years for various things.

-Bill