[vcf-midatlantic] May Repair workshop

[jsalzman at gmail.com]

I did more work with my own recently acquired H89 that I brought. Herb was
eminently helpful in figuring out what I had available, and was able to get
it booted with the disks that came with the acquisition. I spent most of
the weekend working out some of its little issues after it had been sitting
for over 30 years.

The only other thing I spent considerable time with was recapping my Amiga
4000. After recapping, the Amiga rean well, and far more stable than it did
before. There were some signs of damage from leaking capacitors, but it
wasn't bad, and was able to be cleaned up. However, the audio output is
distorted. I believe there was some electrical damage around the audio
amplifier section, probably the op-amps. That will be a future project.

I had received the pledged XT-IDE card kits before the Workshop, so I
brought them with me and soldered those kits together. Tony made sure they
were delivered to the Museum. Unless someone else tries to do anything with
them beforehand, I'll install them at the next Workshop and put some useful
demo software on them.

One of the last things I did before leaving the event was to take a closer
look at the Museum's H-89 that Herb was working on. I pulled the drive
controller card and found a great amount of green rot on the main
controller IC's socket and pins. There was no noticeable damage to the
board.  I replaced the socket and cleaned up the pins of the IC. That
didn't change the behavior of the drive controller, but it was certainly a
needed fix. The rest of the board is all 74XX TTL logic. The board could be
refurbished easily if the primary controller chip is still good. There were
a couple TTL chips that had similar rot on them, but not nearly as bad. It
was running late for me, so I didn't repair/replace those sockets at that
time.

Jeff Salzman

On Tue, May 18, 2021 at 7:50 AM Jeffrey Brace via vcf-midatlantic <
vcf-midatlantic at lists.vcfed.org> wrote:

> Much thanks to Tony and Dean for managing the workshop on Saturday and part
> of Sunday. I had a much needed break from doing the workshops each month.
>
> The May repair workshop had half the number of usual suspects, but a lot
> got done. Lots of good work done by the people there. It also made it
> easier to find a place to go out to dinner as a larger group of 15 is
> harder to accomodate on a Saturday night.
>
> I know that Jeff Salzman and Herb were working on the H89, and got it
> mostly working. So hopefully at the June repair workshop we can get Alex
> Bodnar to come take a look at it since he seems to be highly recommended in
> repairing these machines.
>
> I know that Bill I and Jeff Jonas were making progress in the warehouse.
>
> I'm not sure what else went on. I got there at 1PM on Sunday.
> Maybe others can fill us in on their progress in different areas.
>
> Next repair workshop is June 12 & 13. Look for the next e-mail for the sign
> up.
>
>
> =========================================
> Jeff Brace
> Vice President & Board Member
> Vintage Computer Festival East Show-runner
> Vintage Computer Federation is a 501c3 charity
> http://www.vcfed.org/
> jeffrey at vcfed.org
>