SomeBody wrote:

: I'm working on some 9" monochrome monitors and I've run into some problems
: on many of these units.

These are basic security monitors, it's really a hunt and peck job.

As a couple others have suggested, pull and test all the electolytics in the
horizontal section (areas b1,b2,a1,a2 on the schematic). Anything bipolar
I'd just replace now.

If those come up clean, move on to checking the diodes and resistors.

Usually there is a lot of room to work on these and the card all the
electronics are on can usually be lifted and twisted to access both sides.

With horizontal fold over, there is a slight chance that either transformer
(horz osc and flyback) are bad or shorted. If nothing pops out with the
cap/diode/resistor check, will just have to subsitute these to see.

Really though, just pull and replace any electrolytic that is bipolar or
rated at 160V or over, if it isn't bad now, it will be soon. I'd guess
nearly 80% of the problems these things develop can be fixed by doing that.

-bruce