Agilent Technologies 35670A Service Manual page 186

Troubleshooting the Analyzer
To perform initial verification
Step 7. Check signals required for power up.
G
• Using a logic probe, check the following signals.
Signal Name
PVALID
RSTn
CASn
RASn
VDATA
ASn
• Using a logic probe, check that the following TTL signals are toggling just
after power up.
The signals may stop toggling when the CPU assembly finishes the bootrom self
tests.
Signal Name
PASn
PDSACK1n
PDSACK0n
PRW
PDSn
PA(26)
PA(16)
• If the signals are not correct, the A7 CPU assembly is probably faulty.
• Using a logic probe, check that A7 P7 pin 2 (SCL) and A7 P7 pin 1 (SDA)
toggle TTL states at least twice just after power up.
• If the signals are not correct, the A7 CPU assembly is probably faulty.
• If the signals are correct, go to page 4-15, ''To troubleshoot power-up
failures.''
4-10
Test Location TTL State
A7 P8 pin 3 High
A7 P8 pin 5 High
A7 P7 pin 3 Toggling
A7 P7 pin 4 Toggling
A7 P7 pin 7 Toggling
A7 P6 pin 10 Toggling
Test Location
A7 P8 pin 7
A7 P8 pin 8
A7 P8 pin 9
A7 P8 pin 10
A7 P8 pin 11
A7 P8 pin 12
A7 P8 pin 13
Agilent 35670A
Probable Faulty Assembly
A98 Power Supply
A7 CPU
A7 CPU
A7 CPU
A7 CPU
A7 CPU