Fixing the keys of my Edirol PCR-M50

When I went to use my MIDI keyboard today I found that lots of keys weren't responsive anymore. Well, actually, it's not that they weren't responsive --it was more that they didn't do anything at all when pressed. Which is quite a sad outcome for their purpose in life.

It seems this particular brand and model has this defect; there are several posts and threads mentioning it, and some of them even suggest that the manufacturer would replace some piece or cover the cost of repairs, if under warranty. But unfortunately I just found out about it when the warranty had expired (as it always happens). Not that I would have been able to find a receipt, since it was a gift, and I seriously doubt trace is still storing the receipt almost five years later. And the shop where the keyboard was acquired doesn't even exist anymore (it was the defunct Virgin Megastore at Oxford Street, if I'm right; either that, or the also defunct turnkey at Charing Cross Road).

I had attempted to fix this problem a few months ago. The first suggestion I tried was the easier and also the least effective: just press the non-responsive key several times, frantically, until it begins to respond. It somehow worked, but a few minutes after it stopped working again. I then went for the second suggestion, which implied opening the case and cleaning the internals, just in case there was dust or something blocking the contacts.

PCR M-50 Keys

I spent quite a lot of time dissasembling the keyboard itself. It's very time consuming: you have to loose each spring individually before you can take a key out. Also, you need to do things in a certain order: each black key can only be removed once the surrounding white keys have been removed. Once the bloody 49 keys with their springs had been taken out (by means of an ingenious use of a screw driver to lever/yank the spring out), I could see there was a lot of dust and dirt inside (although I have seen much worse, I must say). So I vacuum-cleaned everything carefully, and then used q tips to clean the small delicate places one by one.

As a cleaning routine it was very hygienic, but it was totally useless for my purpose (i.e. playing music). When I reassembled everything I found that the keys were still not working. I thought that I had had enough, and decided that I would do with whatever working keys I got. In a bad case I could always use the octave up and down keys --the lower octave worked perfectly!

PCR M-50 Springs

My error was not removing the rubber bands and cleaning below them. I thought that if the rubber bands were so closely together with the underneath circuit board, there could not be any trace of dust below. And I was right on that --there wasn't dust. But as I have found today after disassembling the 49 keys with its 14 screws, it's not dust we want to remove from the contacts, but the remains of the rubber contacts.

PCR M-50 rubber bands

I know it sounds confusing, and it won't help that I haven't taken a picture when I removed the bands, but I'll try to explain: underneath those rubber bands there's a couple of golden contacts per key. Those contacts are right below the circles which the key presses when you press the key. Each of those circles has a black round piece which deals with closing the circuit when the key is pressed.

Then the problem is that due to using the keyboard the pieces end up leaving their mark on the golden contacts. It seems that once their mark is in there (a round, ghostly impression of the black pieces), no matter how strong a key is pressed --it won't be reported as a key press. And the solution is very simple.

A pencil eraser.

Yes. A simple pencil eraser. When I read that I couldn't believe it. Cleaning the contacts with a rubber eraser? What's next, drawing circuits with indian ink? But hey, why not? It couldn't be worse; this time there were even more failing keys than the first time I tried to fix it, so it was either attempting this or starting a search for spares.

I first erased the contacts for B-2, which had stopped working six months ago, and was really bugging me: it being in the middle of the keyboard, it's probably one of the closest keys I press to test sounds and patches!

I then reconnected its rubber band (which is quite a tedious process in itself), and tested the keyboard. It worked!! I was ecstatic. Would it work for the rest of keys? I did the same for the rest, even if not all had failed, but just in case. Then tested them again, pressing with a ballpen over the rubber contacts (to avoid getting accidentally electrocuted by pressing some of the metal surfaces and connections you can see in the picture). All the keys worked now, even the highest C! But... would it work with the keys on?

49 keys and their corresponding springs, and 14 screws later, I can proudly say that YES they work!! I have now a functional keyboard again \o/

Syphus and Makunouchi Bento are both awesome

I am a great admirer of Syphus' unbelievable ability to build cool chiptunes, but after watching this video I'm just so sad he's decided to leave his gigs on hold indefinitely (since I haven't had any opportunity to watch him live):

SYPHUS_LIVE_10.08.10 from Cerebral Scars on Vimeo.

A chiptune artist who does actually do more than pressing buttons in a Gameboy on stage! He's playing real instruments, and the songs are good! Oh yes.

And in a totally different mood: Makunouchi Bento. Hailing from Timisoara in Romania, and fervently recommended by Kaneel (aka Monsieur Baguette). Their Swimé album has been today's soundtrack. Eerie, atmospheric, intriguing. A very good background for thinking.


"Or so they say..." by xplsv

Or so they say...

This was a total surprise for me. Trace+Mrdoob joined their powers together and built this nice HTML5 Javascript demo called "Or so they say...", using my song "A dream of sorts" as its soundtrack.

It's really interesting to see how the same song inspires different things to each person. I personally didn't picture universes, galaxies and stars when I composed the song. It was more something akin to sulphur, colour gradients and a general blurriness after a long day of driving through Iceland and enjoying exciting, strange and unexpected sights.

I love the demo in itself, but also (obviously!) because it's got my music, and because it is made with Javascript, and anyone can learn from it; and because mrdoob keeps adding new stuff to it and it gets instantly updated, it being an online version; but above of everything, I love it because it really makes sense to call it a demo: it is a true demonstration of what you can do with a nowadays, modern browser.

And this brings me to that absurd rage which is slowly but certainly developing in certain demoscene factions: the ones who exclusively use Windows in their computers and could never understand why people using platforms other than Windows could feel slightly discriminated in the scene. Now they look confused, demanding a video because they WOULD NEVER INSTALL CHROME! A video for an HTML demo! Guys, you're just ridiculous and obviously have lost the entire point of this -- it being that HTML is multiplatform, and allows people using any operating system to access and experience the demo. Right, except probably Mac OS because it's not that good, but anyway, you clearly don't get it, so why not just shut up and experience the same frustration people using Linux have been experiencing for years when you told them to install Windows if they wanted to watch a demo?

Yeah, I'm being slightly cynical here. But only slightly.

In any case, I'm glad these small groups of people are just that--small, and everyone else is a tad more open minded and understands that for the HTML technologies to improve, we really need demos like this which push the browser capabilities even more forward and encourage competition amongst browsers. This can only be good, and I really prefer that to a future where we all use the same cumbersome, tedious operating system and the same cumbersome, tedious browser for tedious, boring stuff. I say, let's bring some fun back to browsers!!

And here's some background about the demo if you're interested.

1-bit music

I have just found this new 1-bit music blog explaining what's all that beeper music about.

I heard about 1-bit music some years ago only; since I never owned an Sinclair Spectrum, and never got to play with one in a silent environment (i.e. not in a mall) I never knew how did the Spectrum's beeper sound like.

I believe the (first and) last time I heard about 1 bit music I also was able to download a ZIP file containing several beeper tunes, but since I don't know which site it was, here's a sample song from the author of the blog (Shiru) at 8 bit collective: River City Rancor

Now I wonder if there's some sort of similar stuff for Arduino. It might be an interesting project to experiment with very lo-fi music.

Update (a few minutes later): maybe that site I mention was this one which has a bunch of 1-bit music from various almighty composers such as Ben Daglish!


I actually recorded this almost a month ago but didn't want to release it then -- so that you wouldn't call me an opportunist! Now, that fascinating volcano keeps erupting and I can't but release this volcano-inspired song: Eyjafjallajökull

It's on soundcloud as well, just in case you're into that:

Eyjafjallajökull by supersole