Hi Phil,

Glad to hear that you found the source of the issue. The TR-707 I had in my workshop was also VERY dirty, in fact so dirty that some of the buttons had unstable response. I have just posted the pics I took of the unit before cleaning.back in 2010. I can really recommend this cleaning... it makes the buttons work like brand new again.

One question Phil, was it corrosion that caused the broken tracks on your 707 or a bad solder

Cheers

Bo