8 Oct
2001
8 Oct
'01
9:27 p.m.
At 23:11 08/10/2001, you wrote:
True....
induce
I've got 4 PETs of various types here: The 2001 & 3016 have transformers
with steel bands around them - the 2001 screen is stable, the 3016 wobbles,
but almost imperceptably.
The 8032 and 8032-SK have a different type of transformer (without the
steel band), and wobble very noticably. It could have been a cost-cutting
exercise by CBM, with the result that the 8032 transformers are breaking
down more quickly.
I shall give it a try tonight.
Hmm, I get tired & clumsy after about 1am - I start losing bits, forgetting
to make sure I'm earthed before touching chips & things. Far safer to
switch the 'phone off and do it straight after work...
--
Cheers, Ade.
Be where it's at, B-Racing!
http://b-racing.co.uk
Well, a screwdriver bit. It's one of those
1.5in long bits which go into a
handle, or drill.
OK. Still a fair size piece of metal to move, and thus a fair size
external field. OK, take the loads off the transformer. Pull the power
connector off the
mainboard, and unplug the cable to the monitor. Is there still the same
stray field (if so, suspect shorted turns or similar in the transformer).
Yes, it's still there, albeit not quite so strongly. Still enough to a noticable vibration in my magnet-on-a-stick.
It does sound as though you have transformer problems. You're making me
curious enough to dig out one of my PETs and experiment with the
transformer sometime just to see what I can detect. No, not
ridiculous (at least, I don't think so), but there is a noticable
increase when the monitor load is added.
Interesting. So it might be PSU problems in the monitor. IIRC the monitor
has a bridge rectifier input circuit. Check all 4 diodes and the
soldering to them. If one is open you might have problems like this. I've not
got around to the multimeter test yet - I need to take the
mainboard out to access the underside, and that's not a task to be
doing at
2:20am....
Odd, I normally do delicate work like that at night. It's the one time
you are not going to be disturbed while working on the system...