This is for the one other person in the world who has this problem.
The Alesis D4 is a drum module from the very early 90's. Given that it's so old, it was only a matter of time before it started acting up, and one day mine did. The screen displayed garbled text and wouldn't operate properly.
At one point, I thought to myself - hey, video game cartridges from the same era used battery-backed memory to save data; perhaps this module does the same? So I opened it up.
Sure enough, a battery was attached to the main board. I removed the battery clamp and replaced the bottom with a wire.
Any reasonably sized 3V button battery will do, I picked one up from the grocery store.
Electrical tape works. Why risk poking a hole in the battery with a soldering iron when a little pressure will do? :þ
There you have it, a fully-functional Alesis D4 more than a decade and a half after its manufacture. I wonder how many of these are left?
Drop me an email if this helped you fix your drum brain. Email because comments are not allowed on this blog as of this writing... both by design and by apathy.