Troubleshooting To A Functional Section - HP 8560E Service Manual

General Troubleshooting

Troubleshooting to a Functional Section

Troubleshooting to a Functional Section
1. Refer to Table 6-1 on page 291
information.
2. If the HP 85629B Test and Adjustment Module (TAM) is available,
refer to "Using the TAM" in this chapter for 8560E instruments.
3. If error messages are displayed, refer to "Error Messages" in this
chapter. You will find both error descriptions and troubleshooting
information.
4. If a signal cannot be seen, and no errors messages are displayed, the
fault is probably in the RF section. Refer to Chapter 11, "RF
Section."
5. Blank displays result from problems caused by either the controller
or display/power-supply sections. Because error messages 700 to 755
caused by the controller section cannot be seen on a blank display,
use the following BASIC program to read these errors over HP-IB. If
the program returns an error code of 0, there are no errors.
10 DIM Err$[128]
20 OUTPUT 718;"ERR?;"
30 ENTER 718; Err$
40 PRINT Err$
50 END
a. If there is no response over HP-IB, set an oscilloscope to the
following settings:
Sweep time ........................................................... ms/div
Amplitude scale ................................................... 1 V/div
b. The signals at A2J202 pin 3 and pin 14 should measure about 4
Vp-p. If the levels are incorrect, refer to Chapter 9 and
troubleshoot the A2 controller assembly.
c. Set the oscilloscope to the following settings:
Sweep time ......................................................... 1 ms/div
Amplitude scale ....................................................2 V/div
d. The signal at A2J202 pin 15 should consist of TTL pulses. If the
signal is at a constant level (high or low), troubleshoot the A2
controller assembly.
6. Display problems on 8560E instruments, such as intensity or
distortion, are caused by either the controller or display/power
supply sections. Refer to Chapter 9 or Chapter 12.
290
for the location of troubleshooting
Chapter 6