Roland AT500 lower keyboard problem

[TRWE]

I would appreciate any advice, please, as to how to diagnose and repair a faulty lower keyboard key (B flat above middle C). It worked one day but not the next. There are no other issues with the instrument which is out of warranty. I have gained access to the inner workings and have released but not yet removed the upper keyboard and Touch Screen panel. There is insufficient visual access at present to identify how the mechanical key function is transformed to an electrical function, i.e silicon rubber membrane contacts, solid state device etc. I am endeavouring to identify a procedure why which to proceed rather than press on blindly, albeit very carefully with dis-assembly, lest I add to my woes. For the moment my assumption is that the failure is associated with the B flat key and a "contact/conversion" mechanism rather than a specific electronic problem. I am in regional Western Australia, far removed from formal Roland service facilities. General internet searches for information have not been fruitful. Kind regards. Trevor.

[andyg]

If, like most instruments these days, it uses rubber strip type contacts, the issue is usually a dirty carbon contact for that note. Takes about two seconds to clean with a Q-tip dipped in a little denatured alcohol. Disassembly takes rather longer. My usual recommendation is to wait until you get a few keys that go dead or intermittent, then do them all in one go. I waited for four keys on my Kawai last time I did this, but none were in mission critical places. If Middle C goes down, you'll want to fix that one right away! :)

[TRWE]

Thanks for that. Given that the instrument is well engineered, my view is that it needs to be dis-assembled in stages to access and remove the lower keyboard. I don't see how the lower keyboard can be otherwise removed from its fixings. In light of the above your advice re waiting for other keys to play up and repairing all at the one time is the best course of action. Thankyou for advancing my education. Kind regards. Trevor.

[Kurzweil]

First remove the top. If it is similar to the older models, there will be three screws from the rear that will enable the top to slide toward the bench. Then the upper keyboard tilts up with the controls etc. There is a row of screws, about three, underneath to release first. Also a screw on either side near the pivots. Then the lower keyboard has another row, about six, closer to the musician (also underneath). Screws at the rear of the keyboard from above also (these are more obvious than the ones that come up from below.)

If cleaning does not do it, you can often swap contact strips with one nearer the top. That Bb won't be so bothersome if it is two from the top.

I don't remember if the AT-500 has a key cover. If it does, there will be a screw on each side holding a little piece of plastic above the roller track. It essentially makes a little gap so that you can lift out the cover. This becomes the #2 task, right after removing the top but before tilting up the controls/solo manual.

[TRWE]

Thanks for your information. It will make the task easier when I decide/need to effect repairs. I will chase up some iso/alcohol cleaning solution when I am in the big city next. Kind regards.Trevor.