25 Jun
2013
25 Jun
'13
7:06 a.m.
On Jun 25, 2013, at 6:52, John Many Jars <john at yoyodyne-propulsion.net> wrote:
My son noticed it first. He said, "that thing
is making a horrible
screeching noise!"
Sounds like a switching power supply issue to me.
I couldn't hear it. At 44 I must be deaf to that
frequency. Anyway,
after a while, the frequency came down to where I could hear it
screeching... and I began to notice what looked like "ripple" on the
display...
...the sound is now loud enough you wouldn't want to use it... and it
mostly doesn't work anyway. Most of the time when you turn it on, the
screen stays blank and the keyboard lights stay on continuously.
My experience with old Mac monitors says flyback. Could it be caps?
Could be the flyback, could be the low-voltage supply. Hard to say.
Either way, though, caps are a good guess.
- Dave