Electronic keyboard repair (I hope)

[Puddin' Man]

Yamaha PSR-12, has maybe 72 keys, around 24 voicings, flexible-speed percussion, canned tunes, etc. About 20 years old.

I turn it on lately, it works fine for 2-10 min., then freezes. The little light that is supposed to come on for beat 1 when one chooses percussion accompaniment locks on. That and the power led are the only things functional.

The case has 2 halves. I workbench the thing turning the business end (with keys and most PCB's) up 90 degrees to tinker, and it plays OK for up to 3 hours (presumably lots longer). I figure the problem has to do with either gravity or heat buildup.

There are PCB's for power and switching, and 2 big PCB's presumably for tone generation, special effects, etc. I tried some ribbon cable connections: wouldn't budge. I'm afraid of breaking a board or connector or ?.

It's gotta be repairable. I think. :-)

Any/all help/advice much appreciated. Know of a more productive forum for the query?

Thx, Puddin'

"Well, there's two trains runnin'. Ain't neither one goin' my way. One run at midnight, the other run just before day." - from "Still A Fool", Muddy Waters, maybe 1949

[Nate Nagel]

Clean it real well. My laptop started randomly shutting off/locking up and I just blew the guts out with compressed air and it's still working fine. Dust buildup was causing something crucial to overheat.

nate

[buffalobill]

buffalo ny: just guessing: i don't know this device but if the power is a problem: the ac adapter or input power circuit has some ac ripple as it aged causing freezeup. if this is an ac/dv device, do the symptoms change when you run it on batteries? or in the battery compartmant is there any corrosion present? any defective ac filter capacitors bulging their tops? i just found this:

[JoeSpareBedroom]

Post this in alt.guitar.bass. Don't ask why.

[Puddin' Man]

First thing I do if I have to open the case (any case).

This one was pretty clean. I vacuumed etc anyway.

P

"Well, there's two trains runnin'. Ain't neither one goin' my way. One run at midnight, the other run just before day." - from "Still A Fool", Muddy Waters, maybe 1949

[Puddin' Man]

No corrosion.

The unit runs on 9-12v dc. I just measured about 9v dv off the switch/volume PCB while it was frozen. So the problem is "down the line".

Got it. Much thanks.

P

"Well, there's two trains runnin'. Ain't neither one goin' my way. One run at midnight, the other run just before day." - from "Still A Fool", Muddy Waters, maybe 1949

[Puddin' Man]

Done. Thanks.

P

"Well, there's two trains runnin'. Ain't neither one goin' my way. One run at midnight, the other run just before day." - from "Still A Fool", Muddy Waters, maybe 1949

[JoeSpareBedroom]

Many of the people there have experience with equipment other than bass, and they're all into tinkering. Give it 48 hours and you should have a few responses.