Excercising vintage items - was: Commodore 8010 IEEE-488

From: Dave Dunfield <dave04a_at_dunfield.com>
Date: Thu Oct 21 06:39:57 2004

>I'm with you in this. I like to have all my collection working (some of
>it I use -- this PC is well over 10 years old, heck the linux distro I'm
>running is getting towards being on-topic). I enjoy tracking down faults,
>I enjoy fixing them, and I enjoy seeing how a machine was designed and
>built back then.
>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.

I always apply initial power through a current limiter (light bulb),
which also gives me a visual indication as to how much power it is

If possible, I disconnect the power-supply and energize it separately,
measuring voltages. If it's analog, I ramp it up through a variac,
monitoring the outputs and current draw as it comes up to operating

If I can't disconnect the supply, I disconnect what I can, and pull
anything socketed that I would have a tough time replacing. I don't
like running equipment I am not familier with chips pulled - so I
do so only long enough to verify that all power rails come up right.

Recheck power rails with everything connected.

Once powered up, I scope the power-rails to check for excess noise,
hum etc. If the equipment does not "come up", I shut it down and
do another visual. Then it's on to normal circuit debugging.

The above routine may vary from one piece of equipment to another,
depending on it's exact characteristics...

Anything you would add?

dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Vintage computing equipment collector.
Received on Thu Oct 21 2004 - 06:39:57 BST

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