A little while ago, as you might remember, I picked up a MIDI keyboard so that I could goof around with making music. At least, music in key-form. This worked out pretty well, but I found that there was some friction with plugging the keyboard into my computer, booting up some synth software, setting up the instruments, etc...
So the other day while I was drifting through eBay, I happened upon a listing for a Yamaha Reface CS for a suspiciously low price. Of course the unit was marked as "Parts or Repair Only" which is music to my ears, and scanning the description showed that the speakers were apparently blown but the rest of the keyboard worked as expected.
Well, not having working speakers wouldn't really do well for me, as having to hook up the keyboard to an external amp wouldn't be much different than having to hook up my MIDI keyboard to my computer. But then, just as I was closing the tab, my finger slipped and...
Oh fiddlesticks, I guess I'll just have to fix it.
Now on the bright side, a new set of speakers for one of these Reface models is only about $35 and still in production, but before I fired up an order I figured I should at least do some due diligence to see if I could reproduce the problem.
Now you might have noticed something in the photo: there's a little 1/4 to 3.5 adapter plugged into the keyboard. I'll admit I thought the same thing you probably did: they probably forgot that this adapter was in the headphone jack, and having the adapter there would mute the speakers.
But alas no, it was in the line out port.
And removing it had no effect. Oh well, free 1/4" adapter I guess.
Well, let's put that adapter to use at least and see if the keyboard is functioning with it.
And indeed it is, so that's good.
So a new set of speakers it is... except there's something not quite right, still. This keyboard has stereo speakers, and neither of them is making any sound at all. Not a very quiet whimper; not some scratchy, distorted noise; not a single peep. That's peculiar. Very peculiar indeed.
Hmm, I wonder...
You know, just to be on the safe side, since who knows what configuration parameters the previous owner might have changed (inadvertently or otherwise), let's do a quick factory reset.
And wouldn't you know it, the speakers work just fine once you actually turn them on. There's nothing wrong with this keyboard at all.
Well, nothing critically wrong, that is.
As is the case with anything that has a battery compartment, at some point someone will inevitably leave some batteries in it. This keyboard is no exception, and the previous owner had somehow even left 5 (not 6???) alkalines in the unit. There were also signs of leakage, though curiously not from this set of batteries.
In particular, this pair of terminals was a little crunchy, though luckily they weren't too damaged.
And the foam on the lid had soaked up quite a bit of electrolyte.
So it's plain white vinegar to the rescue to neutralize the caustic goo.
And while there's still a bit of rust staining left on the foam pads, things are basically clean again.
So, let's pop some batteries in there. Some nice NiMH cells that won't leak and destroy everything.
But that's peculiar, when I switch the unit on it acts like the batteries are almost completely dead, even though I just charged these.
Though, this one cell does look a bit lower than the others.
Ignore the negative voltage, the leads are reversed.
And with the unit powered on...
Ah, yes, it definitely shouldn't be reading -1 volts across this cell. For comparison, we'll pop one of the alkalines in its place.
And with the power on, and the leads the right way around this time...
Ok, that's much better, and the keyboard is functioning perfectly on battery power now too. I guess I'll order up some new NiMH cells, these ones are probably 15 years old at this point.
Well, just one final step left to go: update the firmware. That means plugging it in via USB.
Damn, it's a good thing I don't throw out old cables.
And install the update.
Then with just a little bit of cleaning to wipe off the leftover finger-schmoo from the previous owner...
It's looking as good as new.
And the only thing left to do is to make some noise with my extra-loud fidget toy.