HP HP-97 - Page 105

HP-97 Component-Level Maintenance
Table 4-13. Logic PCA Troubleshooting Procedure (Continued)
STEP ACTION
If waveforms are satisfactory,
and VSS > 6.5 Vdc, check Q3
and CR9. Then return to step
6.
If 6.0 =< VSS =< 6.5 Vdc
measure the ripple on VSS.
If ripple is greater than
200 mV, go to step 16.
If VSS < 6.0 Vde, go to step
17.
16.
Check CR5, C4 and the traces
between the VSS line and Ci. Repair as required. Then
return to step 6.
17.
Replace ICs as required. When VSS > 6.0 Vde, return to
step 6.
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