GO to http://www.jz-server.de/casiology/manuals_s.html

and download the service manual. On page (12), it should show you the
power supply circuit.....you want to get a voltage meter and measure
the voltages out all those points (i.e VH 7.5v, VE 3.35V etc.). If all
of the voltages seem correct, you can probably rule out it being a
power supply issue.

If it's not that, it could be possible the the ROM chip is dead
(upd23c256). The SK-1 stores the firmware in this ROM (along with
sounds) which is loaded into the CPU each time you power on the
machine. If this chip is dead, the SK-1 will power on but be
non-operatable.

I can burn you a new ROM for replacement, if you think it's worth a
shot, if you send me a few dollars to cover the cost of a new eprom (i
actually use a modern day flash eprom) and shipping.

Contact me off list if your interested.

--- In CasioSK@yahoogroups.com, "lx_rudis" <lx_rudis@...> wrote:
>
> i've got an sk1 that makes a continuous highpitched whine, buttons
and keys do not work.
> instrument is clean - no whacks on it, has never been opened up and
bent.
>
> anyone been able to repair an sk in such a condition? initially i
figured that the main chip
> had failed, but now i'm wondering if there might be something less
traumatic going on in
> there.
>
> no worries either way, in a worst case i can use this one for what i
bought it for: to replace
> the badly beaten-up case of my main sk1...
>