To the dustbin and back again, the story of Roland TR-707

Original state as found

I was contacted by the customer that he found 707 by the bins. He sent me picture and I knew Id need rubber gloves to work on this one but gladly accepted the job. I was quite surprised apart of the missing battery tray lid everything was there and undamaged.

following a proper bath in soapy water the case looks simply brand new. Awesome condition

When I had the unit clean enough to touch it thorough inspection revealed there was a crack in the PCB where the power connector resides. It is the most frequent place to get fractures as the unit falls on the back while the connector is plugged in.

cracked PCB
tidy up
reinforcement added
final repair before the crack itself was reinforced with glue.

Following the broken trace repair unit sprung to life and booted alright. Unit was however acting very oddly and most of the sounds were crackly and distorted. It was caused by open circuit or intermittent circuit on the slider pots. I took all of them, apart and carefully cleaned and put them back together. This brought all but two of them back to life. Final one to tackle was rimshot/cowbell. Carbon track looked ok but it behaved as if the leg of the slider pot came detached from the carbon track underneath the plastic. I had to carefully remove the plastic and then i applied conductive paint. It restored most of the connection but there was another part of the track I had to fix with carbon paint.

Sadly it is not possible to source replacement sliders for those anymore. It would have been much easier just to fit a new set of sliders and be done with it.