Roland E-20 synthesiser keyboard

I expect you're going to have to open it up. Since you already have one strictly mechanical issue with the keyboard--the misplaced key--I think it's reasonable to at least suspect mechanical issues with the other two. In any case, it's going to have to come open to fix the one key; so repost if you can't figure out the problem with the other two *after* you've looked inside.

jak

I'm not familiar at all with this specific model, but from your description it certainly sounds like some mechanical damage to or maladjustment of the keyboard assembly. Disassembly and inspection should eventually reveal what the problem is, and likely also if it is feasible to make/invent a repair or not.

The electronics almost certainly uses some form of matrixed scanning of the keys to then digitally activate the sounds, perhaps in octave or half octave increments, so the actual electronic core would seem to be perfectly OK and the problems lie only in the keyboard mechanism itself or its interconnection to the "brain."

Good luck.

The key that is sticking up is almost certainly broken. The keys that don't sound are almost certainly because the key contacts are dirty or worn.

You don't need a service manual. Just take off the lower casing and work out what is required to remove the keyframe assembly - usually unscrewing lots of screws and perhaps removing some circuit boards. The key contact strips are under the keys. On some keyboards you need to remove the keys to access them, on others you unscrew the circuit boards from under the keys to access them leaving the keys in place.

You may be able to clean the dirtry strips and the PCB they act on, or it may be better to buy a new set of strips with the new key you will need to buy from Roland, neither are particularly expensive. Clean the PCB contacts carefully with alcohol and cotton buds before fitting the new or cleaned strips.

Gareth.

Thanks for the responses guys. I will probably be ok once I manage to get into the beast (one of the reasons I was after a service manual). So far have removed all of the arrowed screws on the underside together with a couple that were not arrowed. (7 x 20mm round head, 2 x 12mm roundhead and 2 x 20mm countersunk).The only ones I have not removed are four marked "Do Not Remove" (natch!). Judging by the spacing I think they are probably securing the power supply/transformer. The top does still not want to part company with the bottom and I do not want to start jemmying. It seems to seperate by about 20mm all the way round except at the back.

Roy

Use something like a heavy guitar pick to work around the seam. Likely either top needs to flex in, or vice versa, to release a tab.

(Almost as likely: you've already figured this out....)

jak

This probably goes without saying, but it might be necessary to remove any grub nuts, binding screws, etc. from the various connectors on the back panel and/or knobs etc. from the switchgear on top.

Hi again guys, finally managed to get into the beast. The screw in the middle was an absolute pig to remove. Turning the unit rightside up, I was able to flip the lid over to the rear. This revealed a pleasant surprise, not a surface mount component in sight! Oh Joy!. The keyboard itself was a complete unit retained by 4 screws into the cabinet base, electrically connected via a pcb connector on a short ribbon cable to one of the main boards so I was able to remove it in its entirety. The contacts, if you can call them that, look like short lengths of springy heavy gauge silvered guitar string, soldered at pcb ends and passing between two wire contacts to the end of the key. The wires to the ends of the dead keys had popped out of the ends of the keys. Fixed in a jiffy! The other fault with the key standing proud of the others seems to be the loss of a plastic or rubber stop which fits on a metal tab beneath the key. It doesnt seem to be floating around in the cabinet anywhere so I will probably improvise something ie bit of coax sleeving or somesuch. I an going to have to remove the key to get at it though - and its not immediately apparent what holds the keys on. Thanks for all the help and advice so far.

Roy

roundhead

cannot

can

to

of

remove

I usually use a bit of silicone sleeving for those rubbery things. If it is the wrong sort of material it grabs at the key, it should be only slightly resistive to motion , ie a damper of sorts AFAIK. You may want to swap it/them with those under keys at the, less used, high or low end of the keyboard as they are quite critical to the action of the keys.

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on