Menu
Roland TR707 Repair
Roland TR707 Repair:
The first thing to check was the usual power supply suspects:
We did notice that the supplied adjustable ‘wall wart’ was outputting 20V when set to 12V and after further testing discovered that when set to 7.5V it output just over 12V which was ok for the unit. The fact that these were all good….was not good news.
After some diagnostics involving the boot up reset circuits etc I managed to get signs of life. However, there were a number of the buttons not working (STOP being one of them), ACCENT was not working and several voices were not sounding. Pattern play worked but Track play did nothing. It would also not boot up into test mode either.
More probing and head scratching, swapping over some logic ICs after sockets were installed, buttons cleaned, membrane cleaned, diodes tested and eventually she started behaving properly and test mode was achieved.
Thinking she was then finished there was an issue with no Hi- hats.
The missing hi-hat signal was caused by the Roland capacitor adhesive turning corrosive and eating away trace/component legs and a jumper wire.
Once this was sorted out and the faders cleaned the factory patches were loaded in and voila she lives.
