Audio Drive ES688 ISA Sound Card - Capacitor Replacement

I’ve recently came into having one of these on loan. Noticed the capacitors are starting to bulge and we have a fair amount of corrosion and rust present. Checked with the owners and got the green-light to do some preventative maintenance.

I haven’t connected this card to anything so I don’t know if it works at all or has any secondary faults. If @SuperNick can get his Dasher 386 fired up for RetroChallenge 2022/10, this card might be able to work in it for enhanced audio beyond PC speaker sounds.

Conveniently, I have all the required capacitors on hand to rebuild this. We’re selecting mostly low ESR capacitors that fit the existing silk screen but are allowing for double height capacitors that should still stay within the confines of the card.

Here’s the action plan:

  • Remove all jumpers after noting where they are.
  • Clean the board with bicarbonate soda mixed with water to become a paste.
  • Brush lightly around all the chips and components.
  • Add vinegar the card to make it shine and remove the bicarb.
  • Wash in tap water.
  • Wash in a distilled water bath.
  • Leave to dry for several days.
  • Replace all capacitors.
  • Add CRC 2-26 to the volume control wheel to remove static.

Quite a few steps ahead but it should be quite an enjoyable little project. Here’s some photos of the front and rear of the board as well as the ports.

With a bit of elbow grease, luck and hope, we might have this working before the month is out. :upside_down_face:

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