In article , "JANA" wrote:
Use a heat gun, and freeze spray on all the components in the power supply,
and scan areas to start with. The work your way through the video path. You
can try working in sections to start with. Eventually, you should get it
down to the component that is the cause. The fault may be a cap, or any
other type of component that became temperature sensitive. Don't rule out
cold solder connections, and the possibility of the CRT itself becoming
intermittent. I have seen all kinds of things cause thermo problems.


I did try using the cooling spray on it while it was in the state of the blue
channel just having dropped out, no results. But to do it properly, I should
go back and try using the heat gun to see if I can force it into that state by
localising the defect. And being that it is a fairly sparse boards, it won't
be a big problem to reheat any of the solder joints. It's just been a bit of
lazyness on my part as it's a rackmount unit and it's a bit of pain to pull it
out, and I have 4 other monitors of the same family to fall back on, so it's
never been a situation of being completely down...yet...
Thanks again for the good advice, and reminding me about trying the
heat gun. I've had one situation where I was using the heat and cool method
and the heat provided just enough energy to cause a catastophic failure in a
large passbank laser power supply, so I suspect I may be a bit "gunshy"..
Well, now to go search out some canned cold. I'm up in British Columbia,
and since moving here from the US a few years back, it kills me when I see
what they get for stuff like that here. A simple can of low quality dust off
goes for $12-17 here, just insane.. On the other hand, in the few moments
when I look up from the monitors, I'm looking out at mountains and ocean
that looks like something from Natl. Geographic..poor me..wasting away
editing video..

Thanks!
Doug

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