Kurzweil PC88 - Page 83

Chapter 4 Troubleshooting
Power Problems
On power up no Audio, LEDs or LCD.
AC Adaptor
1. Check that the AC adaptor is properly connected to
the unit and a power source.
2. Set the DVM for AC, 20 Volts. With a DVM and
the AC adaptor plugged into an AC socket, check to
see that you are reading approximately 10 Volts AC
at the jack.
3. If not, disconnect the AC adaptor from the AC
socket. Remove the 4 screws on the prong side of
the adaptor and check the fuse.
If the fuse is bad, replace it with a 5A, 250V Slo-Blo,
Pigtail.
4. If the fuse is not the problem, order a new AC
adaptor. Kurzweil Part Number, D52001000.
Note: Any reference to pins of devices, assume that
the PC88 Top Cover is in the service position; face
down, rear panel edge towards you.
AC Receptacle
1. With the unit open, connect the AC adaptor to the
unit. Be sure the power switch is in the "off"
position and the AC adaptor is plugged into the AC
outlet.
2. Set the DVM for AC, 20 Volts. Place one probe at
the center contact of the AC receptacle, J305. Place
the second probe on the bridge rectifier, D14, third
pin from the right. You should read 10 Volts or
greater.
3. The AC receptacle is functional.
PC88 Service Manual
4-3