Read/Write System, Functional Diagram - HP 7925D Service Manual

Troubleshooting
NOTES:
1. Refer to the following diagram for circuit details.
• Read/Write System Functional Diagram, fig. 4-28.
2. PCA's associated with R. W malfunction include:
• I/O sector PCA·A2/microprocessor.
• Drive Control PCA-A4.
No
J
URG signal probably active.
~--------'
7925
Replace PCA-A2. If malfunction remains,
replace PCA-A4. If malfunction remains,
check current path from A2P2-K to A4P2-K
for open circuit.
Replace PCA-A4.
If
malfunction remains,
replace PCA-A2.
If
malfunction remains,
check current paths from A2P2-9 to A4P2-9
and from A2P2-K to A4P2-K for open circuit.
7311-8A
4-16
Figure 4-6.
R. W LED Indicator Troubleshooting Flowchart