yes, i do more than guitar stuff.
this belongs to a friend of mine, it was in sad shape. his start stop button had quit working and the cover popped off (and was chewed by the dog), four of his step buttons were broken off, and all the pots and switches were so dirty and dusty that they either didn't work or were so scratchy they were un-usable.
the step switches were replaced with a set found on ebay, and they work fairly well- some require a harder press than others. these are getting really hard to find so get em now if you need them- or ever might...
someone, before my friend owned it, had modded it- and done a pretty good job for the most part... he added a bass drum tuning knob, a snare filter knob and a snare decay knob... however, the snare drum mods wound up giving the snare drum a constant hum in the background. i was asked to give the mods off switches that could return the unit to stock and do a general cleaning and refurbishing.
here are the new switches and pots (they were beyond cleaning, easier to just replace) for the mods... and below are the mods themselves- the first is the bassdrum tuning and second is snare decay. forgot to take a picture of the snare filter mod, sorry... i'm sure its on google somewhere.
to try and keep the unit as original as possible, and avoid cutting or drilling into the top of the machine, i gave it a new start/stop switch that is soldered to the main board in place of the original one, so if a new button is found it could be swapped out then. until then you just have to press the button through the hole where the button cover would be. you can see the new white button in the photo below.
finally, i cleaned all the pots and switches and they are all back in working order with no dust noise.
thats it, its a great machine and a joy to work on.