HP 3562A, Service Manual

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MODE L 3562A
S E RVICE
A . Initial CondHtions Test
1 . Disconnect the power cable from the rear panel and remove the top cover. Place the
A2 CPU/H P I B on the 03562-66540 extender board .
2. Connect the power cable and press the l ine switch on.
3. Check the fol lowing for correct value:
Signal Location Value
+ 5 S A2 TP2 + 5 ± O.3V
PWRU P A2 )1 5-2 TTL logic 1
PWRDNL A2 ) 1 6-2 TTL logic 1
HALTL A2 U1 00-1 7 TTL logic 1
RESETL
A2 U1 00-1 8 TTL logic 1
8 mHz C lock A2 TP5 Refer to waveform #1 (Cl
4. If the + 55, PWRUP, or PWRONL are not the correct val ues, go to paragraph 8-1 6,
"A1 8 Power Supply Assembly."
5. If the cause of the fai l u re is stil l not found, go to the signature tests (F).
B. System CPU Diagnostics
The CPU diagnostics do the fol lowing at power up or when the CPU is reset by pressing
A2 S1 :
1 . Flashes the L E Os and then turns each one on starting with 053-1 (MSB).
2. Clears the test log.
3. Stores address and contents of NVRAM.
4. Check sums the mon itor ROM.
5 . Exerc ises several system processor (U1 00) instructions.
6. Tests the mon itor RAM by writing and read ing patterns to and from it.
7. If an error was fou nd in the RAM test, the add ress decoder is exerc ised by writing
addresses to several locations and reading the contents.
8. Tests the NVRAM using a write/read/restore sequence on each memory location.
9. Tests the timer and interru pt c i rcu its.
The CPU diagnostics stop when a fau lt is fou nd and display the error code on the test
LEDs (A2 053, A2 054). If no error is fou nd on the A2 CPU/H P I B assembly, the power-up
sequence continues. Use table A2-1 to determ ine the most l ikely fai l u re causing an
A2 CPU/H P I B error code.
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