Troubleshooting - HP LOGIC PULSER 546A Operating And Service Manual

Model 546A
Page 31
TROUBLESHOOTING
To troubleshoot a malfunction in the Pulser's operation, conduct the performance tests to determine
specific symptoms then refer to Table 5 for the most likely cause of the problem.
NOTE
To check integrated circuit U1, measure the voltage at pin 5 for 2.7 (±0.3)
volts. Check pin 7 with a scope for the clock waveform shown on the sche-
matic diagram.
Table 5. Troubleshooting Isolation
Symptom
Check (in order listed)
No output-no LED indication Power cable W2, U1, Q3, 51, C6, CS, R3, and C7
No "1" or "0" output U1, C1, Q2, Q1, and C4
No "1" output Q1, U1, CR1, C2, and RS
No "0" output Q2 and U1
Overcurrent shutdown fails to operate
U1, C1, and R2
Program mode failure U1, Q3, and 51