State- And Trace-Storage Problems - HP 8560A Service Manual

1. Disconnect W22 from A2J8.
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 A2J8.
b. Set the HP 8560A to the following settings:
SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..Zero Span
SWEEP TIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20ms
c. Monitor the signal at A2J2 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 A15J302. If the signal is not present at A15J302, the Al5 RF
assembly is probably defective.

State- and Trace-Storage Problems

STATE storage is in the two Program RAMS and TRACE storage is in the two Display
RAM . With low battery voltage, it is normal for STATE
S
power is off for less than one minute. If the power is left off for more than thirty minutes with
low battery voltage, the stored STATE
battery backup:
1. Measure the voltage on W6 at A2JlO. If the voltage is less than 2.6 V, check the BTl
battery.
2. If the battery voltage is correct, reconnect W6 to A2J10, set the analyzer's power off and
wait five minutes.
3. Measure the voltage at A2UlOl pin 28 and A2U102 pin 28.
4. If the voltage is less than 2.0 V dc, the RAM power battery-backup circuitry on the A2
Controller assembly is probably at fault.
and TRACE
S
and TRACE will be lost. The following steps test
S S
to be retained if the
S
Controller Section 9- 15