HP 3562A, Service Manual

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MOD E L 3S62A
SERV I C E
8-1 0 A7 FLOATING POINT PROCESSOR
The information in this section shou ld be used to isolate fau lty subblocks in the A7 Floating
Point Processor (FPP). A l l proced u res assume the fau lt iso lation proced u res of Section
VI I have been used to determ ine which board has failed, and the circ u it descriptions of
Section V I are understood.
WARNING
Service procedures described in this section are performed with
the protective co vers removed and power applied. Hazardous
voltage and energy available at many points can, if contacted, result
in personal injury.
CA UTION
Do not insert or remove any 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
Start
Verify
After-Repair
Start troubleshooti ng by perform ing part A, " I n itial Cond itions Test".
The primary troub leshooting method for the FPP is to use the self-tests
to determine which subblocks are operating correctly. Signatu re
analysis is then used to troubleshoot individual subblocks suspected
of fail ing.
For the compo·nent locator and schematic refer to Section IX. For the
location of cables and boards refer to figure 4-1 in Section IV.
Use the oscil loscope waveforms in table A7-8 to verify correct
operation at various test poi nts in the assem bly.
Use tab le A7-9 to determ ine which adjustments and tests need to be
done to complete instrument service.
TrClubleshooting Hints
1 . After the power-u p tests or reset (A2 51 ), the FPP status LE Ds shou Id be changing rapidly.
If the L E Ds are off or the FPP does not respond to any self-tests, the problem is most
l ikely the sequencer, the m icrocode memory, the ALUs control logic, or the contro l
PALs. Use signatu re analysis test #4 to isolate the fai l u re (after perform ing part A).
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