!HELP!! ALTAIR BLEW SMOKE!!!

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Sun May 25 16:14:00 2003

> I just retrieved an Altair 8800B from long term storage. I blew away
> the dust, checked for loose connections, and finally powered it up.
> Lights flickered to life, and then smoke poured from the front panel.
>
> I pulled it apart, and found a very crispy capacitor number C4 on the
> front panel card. My first problem is that this capacitor is so crispy
> that I have no way of determining the proper value. It is (was)
> connected to a voltage regulator marked "F 79MO8 AUC 7535"

The 79M08 is a -8V regulator FWIW...

If you are lucky, and if that was a tantalum bead capacitor, then it
might be the only fault. I've had them go short-circuit for no good
reason and then burn up quite spectacularly. Often the machine carries on
running.

I can't tell you the value (my schematics, in the 'S100 Handbook' don't
show the regulstors), but try someting like 2.2uF as a start.

-tony
Received on Sun May 25 2003 - 16:14:00 BST