PE> On my XT, whenever I used to plug the com port in, I'd often get a spark,
PE> once the serial port was stuffed because of that and needed repair.

PE> I never learnt my lesson, but I've never had a problem
PE> since, on my more modern machines.  Did they improve
PE> that technology or something? The XT was a Commodore PC5.

RS> Its not too clear what you are actually asking me. If
RS> you are asking if you can just forget about the problem
RS> now on your more modern machines, yes, thats basically true.

PE> That's what I'm asking, and why.

RS> The XT has a fault.

PE> And the fault was?

If you ALWAYS get a significant voltage on it just before its connected
to something else, its normally a leakage path in the power supply, and
there is a small possibility of some obscenity with the mains wiring.

If it only happens SOMETIMES, it may be something as simple as the
case not properly earthed and you are using it in a rather high
static environment, say with plastic carpet, and you adequately
discharge the charge on your body with the other stuff just because
their cases are properly earthed and the detail of how you grab the
system when plugging the lead in ensures you are discharged properly.

While you did say at the top that it only happens sometimes,
in some leakage situations the voltage may well be there all the
time and you only notice the effect on connection some of the time.

Basically you would need to work out which of these is the
problem, and thats not that easy to do in your case. And fixing
the power supply isnt that easy if it is at fault, and it wouldnt
normally be economic to replace the power supply in a PC5.

In theory you could check what the power supply is doing about earthing
the case, but thats not completely trivial for you to do either.

RS> The XT is likely fixable so it doesnt
RS> do that, but presumably its binned now.

PE> Seen quite a deal of activity actually.  Gets lent
PE> out to chinese people, and gets used to test comms.

RS> I'd bin it myself. It really isnt worth the effort to fix the fault.

PE> No, it doesn't have a broken comms port at the moment, just that
PE> it still sparks if I'm not careful (or switch the machine off),

Thats what I meant, that its more trouble than its worth
to fix that. with such an ancient XT. I'd bin it myself.

PE> and that many years ago, the com port was actually broken because of that.

Sure, I understood that bit. Did you use the XT at all when you
were seeing those odd effect after the lightning got your Spirit ?

PE> And actually, when I sent it to a repair centre
PE> in Artarmon, the fuckwits wiped my hard disk.  :-(

Yeah, not uncommon. One of the locals, who actually runs a fairly
extensive computer installation as her job, and who was involved in
a considerable legal claim at home, with the legal letters etc on her
home machine, with no backups of any kind, even tho she does backup at
work, had the shit really hit the fan when the local 'repair center'
clown did that to her system. Her boss is a mate of mine with a very gung
ho approach to threatening legal action and he's a huge fellow, absolutely
gigantic. Sure put the wind up the poor service droid, who I also happen
to know very well. He knows just enough to be dangerous.
@EOT:

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