HP 8562E, Service Manual

Page: 372 / 482

1. Disconnect W22 from
2. If a 10 MHz, TTL-level signal is not present at the end of W22, continue with step 3. If a
10 MHz signal is present at W22, proceed as follows:
a. Reconnect W22 to
b. Set the spectrum analyzer to the following settings:
Span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..ZeroSpan
Sweep time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20ms
c. Monitor the signal at pin 21. This is an output of the frequency counter,
HBUCKET PULSE.
d. If HBUCKET PULSE is stuck high, troubleshoot the frequency counter.
3. Check for a 10 MHz signal at If the signal is not present at the Al5 RF
assembly is probably defective.
State- and Trace-Storage Problems
State storage is in the two of the four Program and trace storage is in the two display
With low battery voltage, it is normal for states and traces to be retained if the power
is off for less than 1 minute. If the power is left off for more than thirty minutes with low
battery voltage, the stored states and traces will be lost. The following steps test battery
backup:
1. Measure the voltage on W6 at If the voltage is less than 2.6 V, check the
battery.
2. If the battery voltage is correct, reconnect W6 to turn the analyzer power off and
wait 5 minutes.
3. Measure the voltage at pin 28 and pin 28.
4. If the voltage is less than 2.0 Vdc, the RAM power battery-backup circuitry on the A2
controller assembly is probably at fault.
Controller Section