HP 3562A Service Manual page 479

MOD E L 3562A
A . Initial CondHtions Test
1 . D i sconnect the power cab le from the rear panel and remove the top cover. P lace the
A2 C PU/H P I B on the 03562-66540 exte nder board .
2 . Connect the power cable a n d p ress the l i ne switch o n .
3 . Check the fol lowing for correct value:
Signal
+ 5 S
PWRU P
PWR D N L
H A LTL
R E S E T L
8 m H z C lock
4. If the + 55, PWR U P, or PWRO N L are not the correct val ues, go to paragraph 8-1 6,
"A1 8 Power S u pply Assem bly."
If the cause of the fai l u re is sti l l not found, go to the signatu re tests (F).
5.
B. System CPU Diagnostics
The C P U diagnostics do the fo l lowi n g at power up or when the C PU is reset by pressing
A2 S1 :
1 . Flashes the L E Os and then turns each one on starting with 053-1 (MS B).
2 . C lears the test l og.
3. Stores add ress and conte nts of NVRAM.
4. C heck s u ms the mon itor ROM.
5 .
Exerc ises several system processor (U1 00) i n structions.
6. Tests the mon itor RAM by writi ng and read ing patterns to and from it.
7 . I f a n error was fou nd in the RAM test, the add ress decoder is exerc ised by writing
add resses to several locations and read ing the contents.
8. Tests the NVRAM u s i n g a write/read/restore sequence on each memory location.
9. Tests the timer and i nterru pt c i rcu its.
The CPU d i agnostics stop when a fau lt is fou nd and d is p l ay the error code on the test
L E Ds (A2 053, A2 054). If no e rror is fou nd on the A2 CPU/H P I B asse mb ly, the power-up
sequence conti n ues. Use table A2-1 to determ ine the most l i kely fa i l u re causing an
A2 CP U/H P I B error code.
Location Value
A2 TP2 + 5 ± O.3V
A2 )1 5-2 TTL logic 1
A 2 ) 1 6-2 TTL logic 1
A2 U1 00-1 7 TTL logic 1
TTL logic 1
A 2 U1 00-1 8
A2 TP5 Refer to waveform #1 (Cl
S E RV I C E
8-29