My Boss DR-55 is refusing to program. This project started as part of a news update- Click here.. Basically, I’m having to replace the 4011 chip.. to start with..
Boss DR-55 capacitor change to allow use of TC4011B chips..
From a thread on electro-music forum: “The CD4011 is a bit fussy … a few years ago I repaired one of these machines with a bad 4011, and the replacement…
Boss Dr-55 memory chip replacement. (TC5501P)
This turned out to be remarkably easy! Step 1: de-solder the existing memory chip. This turned out to be an NEC equivalent of the Toshiba TC5501P. So, 22 pins to…
Boss DR-55 memory chip replacement. TC5501P
I have now successfully replaced the memory chip with a new Toshiba TC5501P. I’ve installed it in a socket and it all works. Result! Full details with photos tomorrow.
Battery Clips & Testing | Defective tc5501p ?
I have replaced the battery clip with one that doesn’t have the pp3 clip on it, to save space. I unsoldered the old one, and soldered in the new one,…
Boss DR-55 Project: Fault Finding
So, The 4011 chip didn’t fix it (although I have a 4011UBP on the way). I opened a thread about it here: http://music-electronics-forum.com/t45560/#post472977 I got some good advice and a…
Boss DR-55 4011 Chip replacement. Part 2: Installing IC Socket and new chip.
Here’s part 2 of the replacement of the 4011 chip. I bought a cheap (and very nasty) 29p 14-pin IC socket from Maplins, plus a CD4011Bp (not the correct UBP)…
Boss DR-55 4011 Chip replacement. Part 1: Removal
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…
Maybe this will help : Boss DR-55 Service Manual
I have opened a thread about this on the Music Electronics Forum: http://music-electronics-forum.com/t45560/#post472977
