Victor 9000/Sirius 1 restoration questions

[Tony Duell]

>  A thorough cleaning is in order before you replace
> all that. I bathe my keyboards in a 10-15% solution of
> ammonia and water. I haven't yet disassembled a V9K
> keyboard, but I imagine it's typical as far as
> keyboards go. Remove the plastic and toss it in. If
> you need more details, I'll provide. It works well.

The notes I made when I repaired my Sirius don't say how the keyboard is 
made, but from the schemaitcs, I'll bet it's a Keytronics. There are the 
sadnard pair of Keytronics ASICs linked to a microcontroller (in this 
case an 8021).

The outer casing will come off easily, screws on the bottom I think. Then 
take out all the tiny screws ont he bottom of the PCB and seprate it from 
the keyframe.

Personally, I take the whole lot apart and clean the bits separately. It 
takes longer, but if you get liquid into the foam pads of a Keytroncis, 
it'll squish for a long time....

There are 2 common failure modes of the Keytronics 'swtich'. The foam pad 
between the 2 mylar disks breaks up, or the metalisation on the lower 
mylar disk vanishes. Eary to repair if you can find some spaee assemblies.

-tony