How do I fix a foggy monitor? Condensation?

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Family Man

How do I fix my IBM monitor. It appears increasingly foggy 4 minutes after
power is on. Initially it's clear. Words on the screen are clear and easy to
read. Then, gradually over the following 10 minutes, the screen turns foggy.
Icons are difficult to distinguish. Normal screen writing becomes almost too
foggy to read. Is it condensation? Can I repair this?

I do not have the hardware skills of this group. I'm new at hardware without
experience or training. I am handy with basic PC tools. Can you recommend
anything I can do to fix it myself?
Thanks in advance,
Hank.
 
Well, with your stated experience I would just take the monitor to somebody
who is experienced with them. There is HIGH voltage inside that monitor, it
probably wouldn't kill you but you might get one hell of a kick.

Believe it or not, there is actually a FOCUS knob inside monitors. My guess
is that once the monitor warms up, the focus is incorrect, because of aging
parts their values change. A guy would take the back off of the monitor,
plug it in and wait for it to warm up and be fuzzy. Then he would use a
plastic screwdriver to adjust the focus knob (located near the flyback
transformer). There is 2 knobs inside there, do not mess with the one that
is not the focus knob. But like I said before, take it to somebody who is
familiar with them. A 10 minute job, at most, including the warm up.
Probably only 4 screws holding the back cover on the monitor.

Why they don't allow focus to be adjusted from outside the monitor I do not
understand.

--Dan
 
Family said:
How do I fix my IBM monitor. It appears increasingly foggy 4 minutes after
power is on. Initially it's clear. Words on the screen are clear and easy to
read. Then, gradually over the following 10 minutes, the screen turns foggy.
Icons are difficult to distinguish. Normal screen writing becomes almost too
foggy to read. Is it condensation? Can I repair this?

I do not have the hardware skills of this group. I'm new at hardware without
experience or training. I am handy with basic PC tools. Can you recommend
anything I can do to fix it myself?
Thanks in advance,
Hank.
Click to expand...

No, it's drift in the high voltage section driving it out of focus.
 
I ran insulation tape down my screwdrivers.
I found the two knobs. VR1 and VR2. Adjustment does not effect the focus.
at a guess, someone's been in here before me. They may have adjusted the
focus to the end of the range and when it didin't fix it, broke the plastic
top on the screw. I removed the top and can adjust the screw but it will not
focus.

I do appreciate our help. Any ideas what to do next?

Hank
 
OK. It's around 25 degrees here in New Zealand and I've been trying to keep
the drops of perspiration from dropping onto the circuit and connecting me.

I'll leave it as it is. Thanks for your help.

Hank
 
Family said:
I ran insulation tape down my screwdrivers.
Click to expand...

Better than nothing but still grossly inadequate. It's much better to
use a chopstick with its tip carved to fit. Also don't touch any metal
parts in the monitor, keep 1 hand in your pocket (reduces likelihood of
completing a path for the current to go through your heart), wear
rubber-soled shoes, plug the monitor into an outlet protected by a
ground fault interrupter, and work only while someone else is in the
room with you so they can phone for an ambulance or administer CPR.
I found the two knobs. VR1 and VR2. Adjustment does not
effect the focus. at a guess, someone's been in here before
me. They may have adjusted the focus to the end of the range
and when it didin't fix it, broke the plastic top on the
screw. I removed the top and can adjust the screw but it
will not focus.
Click to expand...

Except on very old monitors, the focus adjustment is on the flyback
transformer assembly, which is that large plastic piece with the heavy
cable going to the side of the picture tube (suction cup there). The
flyback also has a SCREEN adjustment that affects the brightness.
There may be 1 or 2 focus adjustments, and if there are 2, then either
1 is for corner and the other for center focus, or 1 is for vertical
and the other for horizontal focus.

When focus goes bad, it's usually because an electrolytic capacitor has
failed (in main power supply or around flyback) or the voltage
multiplier in the flyback has failed (must change flyback, may not be
cheap).
 
OK. It's around 25 degrees here in New Zealand and I've been trying to keep
the drops of perspiration from dropping onto the circuit and connecting me.

I'll leave it as it is. Thanks for your help.
Click to expand...
I'm a sailor so I am aware that New Zealand prices are high for
natives and cheap for people like me (even with the Canadian dollar,
it's cheaper to refit or even have a boat made in NZ than almost
anywhere else).

But I have to say that monitors are very cheap these days, especially
CRTs (picture tube style). LCD "flat screen" monitors are crowding out
most of them, excepting the huge Diamond and Trintron monitors used
for professional graphics and video editing.

Here in Toronto, 17" monitors from top-end firms go for $150 or less.
Used 19" three-year-old graphics work station monitors aren't much
more. As for 15" Dell and IBM monitors, people throw those out in the
bloody garbage, along with Pentium II towers, Apple Performas and
PowerMacs and Quadras and early laser printers. I've scavenged enough
working Apple circa 1996 gear to run kiddie software for my
three-year-old. It's al System 7.61 or 8.1. People will give you the
RAM.

So I suggest you try swap meets or surplus stores. The heavier sort of
desk-dominating monitor will go very cheaply, because no one wants to
deal with their size, and the slightly inferior LCD picture (in most
cases) is made up for in "cool factor" and space savings.

The equivalent of the Viewsonic 19" LCD I bought last year for $1,100
would cost me about half that, so expect CRT monitors to get even
cheaper.

R.
 
Family said:
It's around 25 degrees here in New Zealand and I've been
trying to keep the drops of perspiration from dropping
onto the circuit and connecting me.
Click to expand...

OUCH! That's living dangerously. :(

Have you tried the sci.electronics.repair newsgroup? If you search it
with Google Groups, you may even find information about your exact
model monitor, sometimes even the same problem. There are also some
websites with free schematics, most of them in Russia, it seems, like
www.radiolocman.com.
 
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