New Yamaha SY77 Owner - Tact Switches, DeoxIT?

[Italo_DX]

I just picked up a near-mint SY77 from craigslist. The owner replaced the LCD backlight recently and it is cosmetically excellent. I noticed, however, that some of the buttons (tact switches) need multiple presses to work. In the 3 hours I've been using it, it seems to be improving. The owner said it had been in storage for a while and not used. He was kind enough to knock $15 off the asking price when he saw that the buttons weren't so great. He highly recommended getting a can of DeoxIT D5, saying that I could open it up and spray some on the buttons to get them working like new.

I've heard that opening the SY77 and getting to the front panel buttons is a real bear. Should I wait to see if they loosen up or dive in and spray the little buttons down and give them a few dozen presses each? Tact switches are small and sealed so I assume it will be tricky getting the solution into the contacts of the switch.

[Zamise]

Try wearing them back in first since its not been used much lately.

My guess is that they are probably encased too, so cleaner prob won't do any good, it might but if you have to replace them may want to try ebay, or http://www.partstore.com/ before you try support@yamaha.com. Seems they arn't as responsive as they use to be for such things.

Might be one of these:

http://www.partstore.com/SearchResults. ... hTerm=True

...you'd have to make sure the part number id matches first and prob need some soldering and screwdriver skills.

[rhino]

The tactile switches are a failure-point on almost all vintage synths. Had to change them all on my SY-77 and SY-99.(as well as many others). Get them from Mouser Electronics (Texas). I'll look and see if I still have the part #.

Yes, getting to them is a long, slow dig...basicly, you turn the keyboard over, take off the back panel, then remove EVERYTHING layer by layer....TAKE NOTES and DRAW PICTURES !! Many parts overlap and screws are covered by the layer above. Chinese puzzel time ! Don't throw away the foil shields.
Parts are cheap - about $0.18 each.

[Italo_DX]

Thanks for the help. I'll give the buttons some time to break in. This synth looks really great, it's obvious that its troubles are due to lack of use rather than abuse. The floppy drive belt appears to be loose as well. I opened it, cleaned the belt with rubbing alcohol and vacuumed out a few dust bunnies. The belt slips more than ever. I ordered these today:

http://www.goldmine-elec-products.com/p ... ber=G17895

I figure I'll find a working replacement. I'm slowly learning the sequencer and have already hashed together a quick tune:



I've yet to delve into programming, but from the hundreds of patches I've sampled, I'm pretty impressed. It can sound very analog at times. More convincing than my D-50 in this regard. It's annoying that you can't save even a single song to the memory. I had to make the demo song in one sitting without switching off the synth. Once I get the floppy drive going things will be more relaxed.

[Virgule]

serious synthesizer
congrats!!

[wildpaws]

There are drive belts marketed specifically as SY77/99 replacement belts, you can usually find them on eBay easily. I buy my belts from a local supplier, an electronics repair shop. The dimensions for the drive belt on SY77/99 disk drives are 9.6"x .025" x .124". There is no non-volatile RAM for savings songs/sequences (pretty normal for workstations from that era), they must be saved to the disk drive or your computer (or you could use a Yamaha MDF-1).
Clyde

[Altitude]

...
Yes, getting to them is a long, slow dig...basicly, you turn the keyboard over, take off the back panel, then remove EVERYTHING layer by layer....TAKE NOTES and DRAW PICTURES !! Many parts overlap and screws are covered by the layer above. Chinese puzzel time ! Don't throw away the foil shields.
Parts are cheap - about $0.18 each.

+1

Digital camera comes in handy here also.

When taking out old switches, just cut away everything so you can desolder the pins easily, you will be tossing the tact anyway and the last thing you want to do is lift a trace or mess up the board getting the old ones out. Tact switches are about as caveman as parts get so a replacement is sure to exist (the tacts in the 303 and 606 are still in production)

[Italo_DX]

Just wanted to reply that the largest of the bands was a perfect fit and the drive works like new!

[Italo_DX]

I have some great news! I finally got around to doing the DeoxIT job on my SY77 and it was a success! My buttons not only work like new, but feel better. I doused them pretty well with the DeoxIT spray and worked them well to get the solution into the switch. While I was in there, I cleaned some dust out of the LCD, too.

I must say though, that after five hours of disassembling, cleaning and reassembling this beast, I feel like I've been hit by a train. It is a very involved job with what seemed like over a hundred screws, many connectors, shields, etc and it all has to go together in just the right order. I'm so glad that the operation was a success!