Polymorph wrote:
On Jan 7, 1:24 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
It may still turn out not to be too hard to fix--just different from
what was expected. ;-)
Well, I'm glad I didn't give up so soon as I am rather happy and (a
little embarassed to find that the solution was so easy) to say that
the problem did appear to be the HV divider. After allowing the
monitor to warm up (approx. 20 - 30 mins), I then adjusted the pots as
Ferdinand described and was able to get a good picture (both focus and
brightness). I left the monitor running for quite a while and it
seemed to keep the brightness and focus settings.
I switched off and unplugged the monitor overnight and retested this
morning. After a brief warm up period (say 30 seconds) the image
became visable with good contrast and focus.
This sounds like a case of what would be called "pot noise" if it
were an audio application. When a pot is seldom changed, the sliding
contact with the carbon element can become dirty/imperfect, and, in
some cases, temperature- or stress-sensitive.
In most of these cases, simply turning the pot several times back and
forth over the normal set point will clean the contact and element and
restore normal function. In extreme cases, use of a specialized cleaner
is called for.
I'm glad that you got it working!
I will do some more testing tonight to determine if this has fully
fixed the problem. I have only been running the monitor with the
textual IIgs startup screen (the one with the Apple flying backwards
and forwards) as I removed all of my prized expansion cards from the
IIgs before testing. When I fire up GS/OS it will give a better
indication of the clarity due to the higher resolution, but from what
I'm seeing, I'm pretty confident it will be OK.
Now if only I had the knowledge to have tried this sooner, I could
have avoided inhaling all of the solder fumes (yes I am aware they are
not good for you and I do avoid them as much as possible!). You live
and you learn.
They can't be too bad for you--I've breathed them (just incidentally)
for years and I'm not dead yet. ;-)
Seriously, lead vapor is a potential issue, but the vapor pressure
of lead is quite low at the melting point of solder. A fume hood
is not justified.
So it would seem that the components in my monitor are not faulty,
just the technician. ;-)
;-) Many times I have made the same observation about myself! ;-)
I'll post back tonight when I get around to doing further testing...
Thanks guys, my daughter will be pleased to get her computer
operational again.
Good for you, for sticking with it and being willing to experiment.