There's just something about the aesthetic of the Boss Dr Rhythm DR-110 that makes it look like something you'd get by trading in an absurd number of cereal box UPCs. The sounds it produces are, from right to left: Raise the Roof, Umbrella, UFO, Umbrella Reflecting Off A Pool, Cat Food, Cranberry Sauce, and Free Public Wi-Fi.
I picked up this classic Roland analog drum machine from Japan because I had bought one (1) memory card for my D-70 and it felt silly to ship that by itself without combining it with something else. Of course by the time it arrived at the forwarding warehouse I'd also bought another rack effects unit and two more memory cards so it would have been fine to just ship those items in a bundle but let's not think too hard about that. The important part is that it was cheap.
And cheap for a reason, of course. The display was suffering from the classic "vinegar syndrome" where the adhesive for the reflective polarizer starts to degrade over time.
This is fine, though. Polarizer film is pretty cheap and easy to apply. Famous last words? Stay tuned, I guess.
But the polarizer degrading isn't the only issue these units tend to face. The other is on the back side.
Why yes, that is a curious stain next to the battery compartment. Very observant of you. Let's have a look inside to see what caused it.
Yup, that would be the usual battery schmoo. Interestingly, despite having more schmoo on them, the contacts on the left that go to the PCB are actually in better condition than the ones on the right that just bridge the batteries together.
Well, it's a good thing that this has a DC input jack.
Speaking of things going in, let's go in ourselves and see how things look inside.
The PCB contact side is looking pretty clean. The schmoo has corroded the traces a little on the main PCB, but very little of it dripped onto the front panel PCB below it.
There was quite a bit more drippage on this side, however, and at least one rivet via there looks like it's unlikely to be conductive anymore.
Well, it's time for the battery-schmoo antidote: plain old white vinegar.
The battery contact is cleaning up pretty quickly, though it's mostly pointless as part of the tab on one side has long since broken off and disappeared.
The battery contact on the main PCB is getting nice and fizzy though, the vinegar is doing a good job here.
Pulling things further apart, we can see the other side of that via on the front panel board.
And yeah, safe to say this isn't going to be very conductive anymore.
Speaking of not conductive, those PCB pads that the carbon pills are supposed to press against are looking a bit grimy. Let's clean them off.
A pencil eraser is the secret weapon here. These contacts are gold plated so they should clean up pretty easily.
And yup, that took off some grime.
Back in vinegar-land, the battery contact is now schmoo-free, for what it's worth.
The contact on the left is supposed to have a piece that folds back down over the front to make contact with the negative end of an AA battery, but as I mentioned, it's long gone. Well, at least it's clean now.
Speaking of clean, the schmoo corroded the surface of some traces around the battery contacts, but somewhat surprisingly none of them are actually broken.
It took off some of the solder mask, but that's not a big deal. Also in case you're wondering the white stuff is just the flux on the board that was left there during manufacturing. I had used some alcohol to clean off the bottom section of the PCB here and the partially removed flux tends to turn pasty white when you do that.
Anyway, there's nothing really to fix on this board, so let's have a look at the front panel board.
And yes, up close this via is looking pretty dire. Scraping back the solder mask reveals a pretty obvious missing section of trace.
On the top side, the same via has another missing section of trace next to it, so it'll need to be repaired on both sides.
So it's magnet wire to the rescue.
And then patch things up with a fresh coat of solder mask.
There were a few other vias around here that had lost their conductivity but I'll save you the excruciating detail on those. It's just more of the same all over again.
So, before we put things back together let's actually see if this thing works.
Well that's an encouraging sign. I don't have the new polarizer film yet but it should be here in about a week or so. For now, we'll just have to deal with the ugliness.
Anyway, with everything back together things are looking much cleaner, and the unit actually works. The buttons all function, the sounds all sound like sound, and the pots aren't exceptionally scratchy.
And just as a reminder, I'll leave you with this photo of the back.
They wrote that there for a reason.
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