Re: OT: Classic Macs group?

["Paul G." <carbide@egine.com>]

On Jun 8, 10:56 am, "Michael J. Mahon" <mjma...@aol.com> wrote:

> If this is the case, look at the few components in the feedback
> circuit that form a low-pass filter.  I'd bet that there's a low-value
> electrolytic capacitor (1-10uF) that has decreased in capacitance.

I think the electrolytic capacitors are quite likely to be the cause.
I have an ESR meter which I built from a kit some years ago when I was
doing a lot of monitor repairs. It measures the "effective series
resistance" of electrolytic capacitors, and works in-circuit. They dry
out with time and heat, and the series resistance rises.

Also look for bulging capacitors. The ends should be flat, if they are
convex the cap has gone bad. My DVD player recently died with a rental
DVD in it. I had to dismantle it to retrieve the DVD, and glancing at
the P/S I noticed one of the electrolytics was bulging at the end. I
replaced it with one removed from a board in my junk box, and it fixed
it.
-Paul