Like Ghettosynth, I'm a qualified repair tech and if something goes wrong, I'm generally able to fix it. I used to work for a music sales and live production company many years ago and they were (and still are) Roland agents so I was able to get parts and schematics for my Roland analog gear quite easily. In 1991, I was GIVEN a Roland System 700 sequencer by a friend who had a complete System 700 and two sequencers, one of which didn't work. He said I could have it and if I could fix it, I could keep it.
It turns out Roland were able to supply me a schematic for it for free and I traced the fault down to a single 4000 series CMOS chip which cost me a couple of dollars from Dick Smith Electronics. I already had the parts to build a simple +-15vDC regulated supply so that sequencer cost me almost nothing.
Other faults I can remember over the years are the floppy drive in my SY77 dying but that was just a belt and easily fixed. It did develop a strange fault where the whole synth would freeze and none of the buttons would work. That also turned out to be quite simple and was a bunch of dry solder joints on the power supply PCB. Easily fixed.
While I was at it, I pulled all the PCBs out and resoldered the joints on the switches, some of which had become difficult to make activate due to dry joints.
My DX7 developed a faulty volume pot and I actually found an exact replacement in the most unlikely of places.... an old telephone with speakerphone function. The speaker volume control was the exact same part as the DX7 volume slider!
My System 100 synth developed a strange fault where the expander oscillator would go WAY out of tune and the audio would drop to almost nothing. That was also a simple repair and was just corrosion on the PCB connectors. That was easily fixed by disconnecting all the connectors and spraying them with Deoxit D5.
My JX3P developed a couple of faults. The first was with the PG200 and that turned out to be the result of something having been spilt inside it before I had purchased it. It turned out to be non corrosive and a cleanup with alcohol fixed that one. The JX itself later developed a fault where the LEDs would start to flicker randomly and the sound would become all garbled before stopping completely. That was caused by a faulty bridge rectifier in the power supply which was trickier to diagnose than to repair because the bridge got hot and the output voltage dropped leading me on a rabbit trail looking for a short somewhere else. Turns out it was an internal fault in the bridge itself.
There's one mechanical fault that I still have to get around to fixing and that is replacing some of the rotor bearings in my Leslie cabinet. However, I've been using VB3 for Hammond duties lately and keep putting that repair off!! I must get around to it though because running guitars and synths through the Leslie is fun! I also want to do some surround experiments using the Leslie mic'd with four mic's.
Over the course of a couple of decades, my Juno 106 developed the now well known 80017a voice chip noise. The first time I fixed this, I was still working for the Roland agent and was able to get a new replacement chip from them quite cheaply. Only recently (a matter of months ago actually) it developed the same fault again with another of the voice chips. This time though, I pulled the faulty chip out (quite a task in itself unless you have a decent desoldering station) and gave it the acetone soak treatment to remove the resin coating. Before reinstalling the chip, I soldered in an inline socket so I can remove it easily if it completely fails in future and needs total replacement. For now though, the acetone soak has fixed it.
There's no doubt a few other things I've forgotten but, overall, I'd have to say hardware has been quite reliable for me. There's the usual routine things like noisy pots which are usually easy to fix with a quick squirt of Deoxit D5... DO NOT use this on slide pots though. It WILL jam them up!
Here's a photo of the Juno 106 voice board with the acetone soaked 80017a chip in its new socket....
![Image](http://stash.reaper.fm/21022/DSC_1653-web.jpg)