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Bultaco
Joined: Feb 14, 2018
Posts: 4
Location: St. Catharines, ON
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 Posted: Wed Feb 14, 2018 6:46 pm Post subject:
Roland U-20 key-contact repair
Subject description: Now that I've got the bottom off, how do I get the keybed out?!? |
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OK, I've apparently performed the EASY part of this repair: removed the 15-or so screws on the bottom of the case.
The unit is now sitting face down on my nice soft table-cloth with all its guts looking up at me. I have a good idea where I have to go and what I have to do (gotta get at those pesky little grey rubber shells/tubs/buttons that contact the PC board when you depress the keys.....and clean them off with alcohol or by scraping or, worst case scenario PAINTING them with that silver-in-a-tube gunk!)......BUT how in hell do I get the keybed OUT of the frame?
There are numerous pc boards (5 I can see) and ribbons (at LEAST 5)...but no obvious place to "start" to get the key-assembly OUTTA there.
Strangely, about 6 people have posted (mostly elsewhere) on the web about how to perform this repair.....and the U-20 is reportedly INfamous for this fault (it's a 'lack-of-use' problem, mostly, so nobody to blame but myself, I KNOW)......but, unfortunately, no one who's done the repair and posted pics of the unit have ever detailed the process as to HOW to get at the offending parts.
Getting the back off......EASY.
Cleaning the contacts........I'LL DO THAT WHEN I GET THERE.
Getting there........THAT is the QUESTION.
Tips? Trick? God forbid........instructions? 
Any help greatly appreciated.
Mike
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Sven
Joined: Mar 10, 2017
Posts: 51
Location: Norway
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Bultaco
Joined: Feb 14, 2018
Posts: 4
Location: St. Catharines, ON
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| Posted: Thu Feb 15, 2018 6:53 am Post subject:
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Hi, Sven.
Thanks for your kind attention to my post.
Yes, I have seen Jim Attwood's article; it was ONE of the ones I stumbled on when searching for guidance on this project.
Unfortunately, his lead paragraph, where he discusses the disassembly, is VERY vague and would have been greatly improved with a video....or at the very least a picture or two.
His two sentences, " You pretty much have to unscrew everything and move the PCB boards out of the way in order to get the keys out of the U-20."....and, " I actually just removed the screws and shifted them around to make clearance so that I could slide the key assembly around.".....don't really tell me anything about where to start or what sequence to follow.
(Not to mention, he was clearly "flying by the seat of his pants", based on the picture and his admission of the sloppy job he did on coating the contacts with Caikote...plus the fact that NOTHING worked when he first "finished" the job!)
There are a TON of screws in the innards of this synth and Jim's assertion that you "have to unscrew EVERYTHING" implies that no two pieces are left joined together.....which is the "amateur overkill" method.
This is a VERY common problem with the U-20, and there are THOUSANDS of them out there, so there must be a "methodical", step-by-step process documented somewhere.
It's not that I'm lazy, don't have the time or the inclination, but every unnecessary screw or component removed increases the risk of damage, improper reassembly and subsequent failure.
Thanks again, Sven...but, STILL HOPING FOR MORE GUIDANCE! |
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Sven
Joined: Mar 10, 2017
Posts: 51
Location: Norway
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| Posted: Thu Feb 15, 2018 7:45 am Post subject:
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Hei,
I understand your critics on the article. I thought it is not detailed enough, but sometimes when you have the thing on the bench it may only need one hint that leads to the right direction
When i first looked at your phto i saw all the white plastic things/studs. Is it possible that Roland used a technique that also calculator manufacturers used for a long time? That these white things where pushed trough the metall and then melted into this cone form to attach everything together? If so it would be almost unreparable.
Wish you good luck
Sven |
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Bultaco
Joined: Feb 14, 2018
Posts: 4
Location: St. Catharines, ON
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| Posted: Thu Feb 15, 2018 7:59 am Post subject:
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| Sven wrote: | Hei,
That these white things where pushed trough the metall and then melted into this cone form to attach everything together? If so it would be almost unreparable.
Wish you good luck
Sven |
Thanks for your "good luck" wishes.
I'm quite sure those plastic "nipples" are just the means of securing the grey rubber contact pads that house the contact "buttons" that complete the circuit to make the sounds. I'm also sure that they can be removed and the repair performed....because a) Attwood did it.....and he's an "amateur" and, in fact, I had this done by the Roland service department in Toronto, just a few years after buying my U-20 new.....about 30 years ago....maybe more!
On your "dumpster" keyboard.....DEFINITELY go get it! Put a fan beside it and blow it dry for several days before turning it on/plugging it in. I pulled a little "strap-on" Yamaha synth/keyboard out of someone's garbage can on the street, decades ago....gave it to my grandsons two years ago...they LOVE it and play it all the time. Best gift (and PRICE) ever! Good luck with THAT!
Here's a link to a YouTube of one exactly like I found in the garbage: https://www.youtube.com/watch?v=RTprQPqUxCE |
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Sven
Joined: Mar 10, 2017
Posts: 51
Location: Norway
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Bultaco
Joined: Feb 14, 2018
Posts: 4
Location: St. Catharines, ON
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| Posted: Thu Feb 15, 2018 3:13 pm Post subject:
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Wow! YOU ARE THE MAN!!Thanks, Sven.
Where on earth did you find this?
I've been going through the diagrams and instructions (such as they are) and I'm starting to think it's not even necessary (or advised) to remove the keybed from the frame in order to get at the contacts. It looks like the factory says you can get at them by simply pulling the keys out one-by-one, from the top.....once you have "unlocked" them underneath.
That, as far as I can tell, would reveal the rubber (or "lubber" as the Japanese pronounce it AND write it on the diagram...LOL) contact pads. It should be possible to pop them out the top then (being careful not to rip off their nipples......if you'll pardon the expression ....and clean them with isopropyl alcohol.
I'll give it a shot and let you know how I make out.
How'd YOU make out with your dumpster diving??! |
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Sven
Joined: Mar 10, 2017
Posts: 51
Location: Norway
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| Posted: Fri Feb 23, 2018 1:06 am Post subject:
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Hello Mike,
did you repaired your keyboard? I picked up the keyboard yesterday, the junkyard only opens on thursdays. Now I will let it dry for 1 week, open it and then maybe let it try one more week. If its not working I hope I can salvage som parts for DIY.
Sven |
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