Excercising vintage items - was: Commodore 8010 IEEE-488

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Thu Oct 21 18:29:08 2004

> >That said, I take some care before applying power. In fact turning it on
> >is one of the last things I do.
>
> Me too.
>
> First I clean out all the dead flies, mice droppings, cobwebs and whatever
> else may have accumulated - this usually involves some level of disassembly,
> which is required anyway for the next step.
>
> Then I do a detailed visual inspection, paying special attention to
> "power" components, looking for discolored capacitors, resistors etc.
> I also look for corrosion in sockets/connectors, and anything else that
> looks at all out of the ordinary - I spend a fair bit of time at this.


At this point, I also check anything mechanical (fans, for example). At
least I make sure they're not totally seized. I may also run motors off a
bench supply to make sure they're OK (with the motor disconnected from
the driver electronics, of course).

I also do ohmmeter checks for dead shorts on power semiconductors
(especially chopper transistors, horizontal output transistors), etc. And
on large electrolytics.

Then I chceck the safety ground (earth) connection is good and that it'll
pass a reasonable current. And I put a megger between the mains input and
the earth connection to check for any serious breakdown.

[...]

> If possible, I disconnect the power-supply and energize it separately,
> measuring voltages. If it's analog, I ramp it up through a variac,

I nearly always find a way to do this....

> monitoring the outputs and current draw as it comes up to operating
> voltage.

I put a dummy load (car bulbs, normally) on the main power rails when
doing this.

-tony
Received on Thu Oct 21 2004 - 18:29:08 BST

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