Kurzweil K250 - Page 88

If a test errror occurs a diagnostic error message wiH be
displayed
on the front panel ,LCD display. If no error occurs, proceed
with the
following.
Disconnect all loopback connectors.
r .
TEST U67 TIMER 1? Press YES
If a test errror occurs a diagnostic error message will be
displayed on the front panel LCD display. If no error occurs, proceed
with the
following.
Press SELECT to exit the CPU tests.
4.11 - POWER FAIL TEST
To check the power fail interrupt logic on the CPU board:
CLR
PWR FAIL CNT? Press YES
Turn off system power, then turn on system power •.
Press SELECT
CLR
PWR FAIL CNT? Press NO
COUNT: 1
The
CO U NT indicates the number of times a power fail
interrupt was detected by the CPU. Cycling the power off then on
several more times and answering NO to the CLR PWR FAIL CNT
prompt should increment the count
by one each time. If the count
does not increment by one, there may be a problem with the
CPU
interrupt logic or the battery-backed RAM.
Kurzwell 250 Service Manual, Chapter 4
4 - 1 8