So my DR-55 isn’t working. It won’t program at all. All I get is the hats.
Based on previous experience with these machines, I’m going to start by replacing the 4011 chip. It’s important to get the RIGHT chip. I’ve had some work fine, but others not, even from the same supplier. The correct chip is the TOSHIBA TC4011UBP.
It turns out that all the nuts and washers are missing off the pots.. suspicious, but it makes this easier..
Follow the pictures above and you’ll see how easy this is..
- Remove knobs and nuts
- Remove screws
- Extract chip.
I now intend to fit a socket and a new 4011 chip.
Look out for part 2 of this (EDIT: now not-so-quick) quick project.
I will eventually create a project page for this..