HP 3562A Service Manual page 453

MOD E L 3562A
8-Si A 1 DIGITAL SOURCE
The information in this section shou ld be u sed to isolate fau lty subblo cks in the A1 Digital
Source assemb ly. A l l procedu res assume the Fau lt I solation proced u res of Section V I I
have been used to determ ine which board has fai led, and the circ u it descriptions of Section
VI are understood.
Service procedures described in this section are performed with
the protective co vers removed and power applied. Hazardous
voltage and energy a vailable at many points can, if contacted, result
in personal injury.
Do not insert or remove an y circuit board in the HP 3562A with
the line power turned on. Power transients caused by insertion or
removal may damage the circuit boards.
How to Use This Section
Stalrt
Reference
Verify
After-Repair
A. lDigital Source Diagnostics
The d igital source is tested using two self-tests; the front end interface test and the source
m a i n test. When either of these tests are i n itiated, the test regi sters and control reg isters
are l oaded with test data and the T E ST s ignal to the test registers goes l ow. The test is
performed and the contents of the status reg isters is read and verified by the A2 System
C P U . Any fai led b its are a n n u n c i ated on the d i s p l ay. These tests are also used in loop
mode for sig natu re analysis patterns.
WARNING
CA UTION
The prim ary method for tro u b l eshooting the d ig ital source assembly
is to use signature analysis and the waveforms provided in parts E and
F. Start trou b leshooti ng by u s i n g part A, "Digital Source Diagnostics"
to isolate the fai l u re to a su bblock.
For the component locato r and sc hematic refer to Section I X. For the
l ocation of cables and boards refer to figu re 4-1 in Section IV.
Use the osc i l l oscope waveforms in table A1 -1 0 to see correct operation
at various test poi nts in the assembly.
Use table A1 -1 1 to determ ine which adj ustments and tests need to be
done to com plete i n stru ment service.
S E RV I C E
8- 3