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View Full Version : IIgs RGB moitor is "jumping"



arfink
September 16th, 2009, 07:24 AM
So my IIgs monitor has a problem- the image jumps intermittently every now and again. Got any ideas? At first I was thinking something came loose when I moved the monitor with me to school, but reseating internal connections didn't help. Tapping the adjustment knobs on the back produces a similar jumping effect; does this mean the pots are bad?

Any ideas?

scommstech
September 16th, 2009, 01:28 PM
So my IIgs monitor has a problem- the image jumps intermittently every now and again. Got any ideas? At first I was thinking something came loose when I moved the monitor with me to school, but reseating internal connections didn't help. Tapping the adjustment knobs on the back produces a similar jumping effect; does this mean the pots are bad?

Any ideas?
Sounds like it. Get some aerosol switch cleaner, and with the monitor
disconnected, and the back off, inject some cleaner into the pot.
Usually there is a small access hole in the pot case.
Exercise the pot, Leave a few minutes then power back on.
Quite common.

nige the hippy
September 17th, 2009, 07:38 AM
This sounds most likely, or it could be a dry/cracked solder joint.
Another possibility, if associated with a "crack" sound is that the EHT can sometimes discharge from under the EHT cap, particularly if the monitor has been damp and dirty. the EHT cap and immediate surroundings can be cleaned with solvent on a rag, and the area smeared with silicone grease.

EXERCISE EXTREME CAUTION IF YOU FIDDLE WITH THIS! and always discharge the EHT with a screwdriver under the cap to earthed chassis (twice!) before touching anything.