Curtis H. Wilbar Jr. wrote:
I was given a Mac Plus a while back... and never tested it....
Decided to give it a quick test...
Other than needing a boot floppy which I'll have to dig up.... it
powers on, video
looks good, monitor is stable and all...
But there is a faint sound (think of it as a cross between crickets
chirping and clicks)
and after a while, it smells to me a bit like ozone at the top of the
Mac.
I'm thinking maybe high voltage leakage ?
Anyone have any experiences with these old Macs that can point me at
what to look
for ?
It might well be OK as it is... but I don't want to risk damage
occuring as other
than a few dings and scrapes and a bit of yellowing, it is in
remarkable condition.
-- Curt
Ozone smell is just the high voltage at work. A slight leakage that may
indicate moisture or excessive dust on the monitor where the HV lead
clips to the side of the picture tube. You might be able to reduce the
smell by opening the case and (after waiting 24 hours to discharge)
clean the glass around the HV Anode clip (may have a rubber disc
protecting the clip) with a red (usually red) fat insulated wire coming
out of the picture tube cone. There is a special coating on the tube
that starts about 2 inches away from the anode clip and coats the glass
cone - do not remove or damage this if possible. It is 1/2 of the
capacitor element of the picture tube Lyden jar type capacitor.
Alternatively the flyback could be damp or filthy with dust. This is
found at the other end of the fat wire (normally red) leading from the
cone of the picture tube. You can wipe it with a damp cloth, taking
particular care not to rotate or move it relative to the frame - as this
will break wires and cause it to fail. Most flybacks are solid enough
that this is not a concern but in my early B&W video game monitors the
flyback coil was not well secured and subject to failure from being
turned or twisted whilst cleanig or just day to day bouncing around...
John :-#)#
--
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
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