A very good video from Scott MacLean with a full JD-800 repair, restoration and modification.
It's a really very complete video, including links for all the parts and products used!
His words:
"The Roland JD-800 is a virtual analog synthesizer produced from 1991 to 1996. Like the D-50, it uses Linear Arithmetic synthesis, which combines samples with digital synthesis. There are 108 built-in waveforms, with the ability to expand this with cards. This is a JD-800 I acquired that was in sad shape - it was suffering greatly from the "red glue of death" - a common problem with Roland synths of the time. This epoxy failure causes sticky, red glue to drip out of the keys and into the synthesizer, gluing keys in place and destroying circuit boards. In this video, I show how I take the synth apart, fix the red glue mess, then do some modifications to the aftertouch and power supply."
Thanks Scott!