12 Aug
2014
12 Aug
'14
10:07 p.m.
Oh, I thought that part was self-evident.. =)
Yes, it's repaired and back in service - time will tell if I +really+ got
it, but what I found most certainly could have completely accounted for the
symptoms.
Flyback primary opens up = video goes off like a switch; no HV = no CRT
current, no image
Flyback primary re-closes = video comes back slowly; HV is there
immediately, but image still waiting on the CRT heater to supply some
electrons
On Tue, Aug 12, 2014 at 7:53 PM, David Griffith <dgriffi at cs.csubak.edu>
wrote:
On Tue, 12 Aug 2014, drlegendre . wrote:
My best Commodore monitor, the 1084, went belly-up on me today. It's been
showing sings of trouble for quite a while, but
this time it finally
failed
over.
[snip]
Anyway, it turns out that this is one of those sets that draws its heater
supply from a second winding on the HV flyback
transformer. After some
inspection of the board, I found that one of the flyback's soldered
mounting pins had cracked at the joint, causing an intermittent
connection.
This was the cause of both symptoms - a quick cut-out of the video when
the
HV disappeared, and the slower fade-in as the connection re-made and the
heater warmup lagged the HV rise.
This seems like bad-news / good-news. It sounds like the problem is
fixable.
--
David Griffith
dgriffi at cs.csubak.edu