Power Problems And Solutions; Troubleshooting - Kurzweil K2661 Musician’s Reference Manual

Power Problems and Solutions

The K2661 is quite tolerant of voltage fluctuations, noise, and transients in the AC power it
receives. The input line filter and grounded power cable will protect against even large amounts
of noise from motors and the like while the built-in filter coupled with the fuse will protect
against all but the largest transients. If your installation is actually suffering from line noise or
transients, most likely your other equipment will be suffering more than your K2661.
Very low line voltage or severe voltage dips are a problem for any computer-based instrument.
When the K2661 is set for 120 volt input (the normal North American setting), it should function
down to 90 volts. If the line voltage drops below 90 volts, a special circuit halts all activity to
protect against software crashes or damage. When the line voltage returns to and stays at an
acceptable level for at least one second, the computer will automatically restart. The net effect is
just as if you had performed a soft reset. Continuous low line voltage or transient dips will never
produce symptoms other than unexpected soft resets as just described. Any other problems such
as distortion, disk errors, or lost data are caused by something other than line voltage
fluctuations.
Soft resets from line voltage dips are most common. These are easily identified because the reset
occurs coincident with the building lights dimming, stage lights or power amps being switched
on, or air-conditioning equipment starting up. The solution in all cases is to get a more direct
connection between your K2661 (and any other computer-based equipment) and the building's
power. Floodlights, large power amplifiers, and motor-operated devices should use a separate
extension cord; preferably they should be plugged into a separate circuit.
Chronic low line voltage is best confirmed by measurement. Readings below 100-105 volts mean
that even small dips could cause resets, while readings below 95 volts (accounting for meter
inaccuracies) are a definite problem. Again, the best solution is to separate your heavy lighting
and amplifier loads from your K2661 and other synths on separate extension cords or separate
circuits when possible. If the actual building voltage is that low, we recommend using an
external step-up transformer or voltage regulator. We do not recommend changing the line
voltage selector to 100 volts (or 230 volts in Europe) because overheating or blown fuses may
occur if you leave the K2661 at the lower setting and use it later at a normal voltage level.

Troubleshooting

If you're not seeing the proper display or hearing the sounds you expect, carefully check the
following things:
• Make sure that your power supply is at the right voltage, and is functioning properly.
• Make sure the power cable is connected properly.
• Adjust the display contrast and brightness if necessary (there are two knobs on the rear
panel). If you still have trouble seeing the display, it's time to contact your dealer.
• Make sure your audio cables are fully connected to the K2661 and to your sound system.
You may want to switch your audio cables, unless you're sure they're functioning properly.
• Check that the K2661's Volume slider is at least partially up.
• Check the volume level of your sound system.
• Lower the volume of your sound system, and turn the K2661 off, then on again (this is called
a power cycle).
• Press the +/-, 0, and Clear buttons (on the alphanumeric buttonpad) at the same time. This is
called a soft reset.
Maintenance and Troubleshooting
Power Problems and Solutions
8-5