Hello! I own an Edirol PCR-50 midi keyboard. I have been pretty inactive with it lately, and I have recently discovered a lot of dead keys.I did pull it apart a bit, and it seems like there are rubber 'bellows' with contact pads in them (seems like two, in order to get velocity data), and I'm thinking they're oxidizing - maybe. The question is - since the rubber sections are glued to the pcb, I didn't want to start tearing them off to check. Anybody know if that's the way to go? If that's what I need to do, I can certainly glue them back on - but I wanted to make sure. Thanks! /Mick
<> wrote in message news:... > Hello! > > I own an Edirol PCR-50 midi keyboard. I have been pretty inactive with > it lately, and I have recently discovered a lot of dead keys.I did pull > it apart a bit, and it seems like there are rubber 'bellows' with > contact pads in them (seems like two, in order to get velocity data), > and I'm thinking they're oxidizing - maybe. The question is - since the > rubber sections are glued to the pcb, I didn't want to start tearing > them off to check. Anybody know if that's the way to go? If that's what > I need to do, I can certainly glue them back on - but I wanted to make > sure. > > Thanks! > > /Mick Mick, I suspect the rubber bellows (silicone rubber probably) support a conductive pad made up of granulated carbon mixed in the plastic. If that is the case, the problem lies with the carbon plastic pad. I have this theory that the carbon is squeezed out over repeated compressions and release. Mcgiver would probably fold some aluminum foil over the pads or glue the foil. I've also had this problem with various tv remote controls. The rubbery bellows are probably available. Korg has replacement parts that fit my Juno's, maybe they would work for you. Joe Rooney
"MickO" <> wrote in message news:... > Joe, thanks for the tip. I'll definitely check it out. One last thing, the rubber is called silastic, might be gray in color. I can't thing of any device I've opened up that had them glued purposefully to the board. Generally, they have little nubs or holes that align things. Maybe years of pepsi cola and sugared coffee spills made it appear that it was glued. Joe
Joe Rooney wrote: > One last thing, the rubber is called silastic, might be gray in color. I > can't thing of any device I've opened up that had them glued purposefully to > the board. Generally, they have little nubs or holes that align things. > Maybe years of pepsi cola and sugared coffee spills made it appear that it > was glued. Eh, umm, yeah. That might have had something to do with it... I'll tear into it as soon as the opportunity presents itself and if interested, I'll post my findings. Thanks for the info!
Ok, so I opened her up, and what I found was pretty interesting. Just as you said - the silastic bellows weren't glued down at all. There were little rubber pins holding them to the PCB. Easy enough. However, by using a thin piece of paper, I managed to figure out that somehow, the dead keys weren't going far down enough. To remedy this, I put little non-metallic motherboard-washers under the screws that hold the PCB down, and thus pushing it a little further up. A lot of the keys that WERE dead are now working just fine. However, there are some keys that still do not work right - however, I don't think it's an electric problem, since pushing the silastic...switch (?) causes MIDI output, but doing the same with a key doesn't, so I'm still thinking there's a mechanical issue. To see some pictures of this open-heart triple-bypass surgery, check out http://www.ohrberg.org/PCR50 And thanks bunches for your help I think I still have to work some more on it, but I'll save that for a rainy day, since it's getting on 10:30pm here, and I have to be at work early, bushy-eyed and bright-tailed in the morning.
