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HP 21-inch Monitor Problem

M

Michael

Jan 1, 1970
0
Hi, all. I have an HP P1110 21" computer monitor here with what looks
like a high voltage problem. Model number is D2847. NDP Chassis 445N.
(That's what it says on the back.)

When first turned on, it looks great. After about 30 seconds, it starts
going out of focus, though size, geometry and everything else look fine.
It stays out of focus for about 30 more seconds and then the
glass-encapsulated spark gap next to the flyback flashes over, making a
pop, and the pic disappears for a second or two. Then it comes back
looking fine, and the cycle repeats.

Seems like the focus voltage must be going up until it arcs the spark
gap. I'm guessing bad flyback. Does that sound right? If so, is it worth
putting one in, or should I just junk the monitor? It makes such a nice
pic that I hate to toss it, but unless the flyback isn't a significant
cost relative to a new monitor, I guess I'll have to... if it is,
indeed, the flyback that's causing this.

Opinions?

Thanks.

Michael
 
J

Jerry G.

Jan 1, 1970
0
This may be a fault in the high voltage multiplier, or where the focus volts
are coupled to the CRT focus grid. This is something that would have to be
serviced properly. Find out who the authorized service rep is for your
monitor, and send it in. Even if you tried to fix this yourself, HP will not
sell you the parts. They only supply parts and service information to their
service reps.

--

Jerry G.
=====


Hi, all. I have an HP P1110 21" computer monitor here with what looks
like a high voltage problem. Model number is D2847. NDP Chassis 445N.
(That's what it says on the back.)

When first turned on, it looks great. After about 30 seconds, it starts
going out of focus, though size, geometry and everything else look fine.
It stays out of focus for about 30 more seconds and then the
glass-encapsulated spark gap next to the flyback flashes over, making a
pop, and the pic disappears for a second or two. Then it comes back
looking fine, and the cycle repeats.

Seems like the focus voltage must be going up until it arcs the spark
gap. I'm guessing bad flyback. Does that sound right? If so, is it worth
putting one in, or should I just junk the monitor? It makes such a nice
pic that I hate to toss it, but unless the flyback isn't a significant
cost relative to a new monitor, I guess I'll have to... if it is,
indeed, the flyback that's causing this.

Opinions?

Thanks.

Michael
 
D

David

Jan 1, 1970
0
Could be the focus divider part of the flyback has an open or is arcing over
internally. Could be an open ground on the flyback focus divider. Both
fairly common.

Also could be a bad picture tube with an open to the focus pin, or a focus
to G2 leakage short internally.

Only proper troubleshooting and measurements of what is going on will
determine the real source of the problem.

David
 
M

Michael

Jan 1, 1970
0
Thanks for the advice. Bad flyback or bad picture tube would both not be
worth fixing, as far as I'm concerned (unless you know of a cheap
flyback source). Guess I'll toss it.

Sincerely,
Michael
 
M

Michael

Jan 1, 1970
0
Fixed it! I took a good look around the flyback and noticed that a few
solder joints looked a bit funky, especially the ones at a trimpot that
was connected through a couple of resistors to that encapsulated spark
gap that kept flashing over. So, I resoldered everything in the area. In
my experience, shotgunning hardly ever works, but it did this time!
Fired the monitor up and she's running like new.

Michael
 
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