Troubleshooting
To test the hard disk drive voltages
Disk Drive Voltages
Pin | Signal Description |
1Reset
2Ground
3Data
4Data
5Data
6Data
7Data
8Data
9Data
10Data
11Data
12Data
13Data
14Data
Pin | Signal Description |
15Data
16Data
17Data
18Data
19Ground
20(connector key pin)
21NC
22Ground
23Write Strobe
24Ground
25Read Strobe
26Ground
27I/O Cycle Extend
28NC
Pin | Signal Description |
29+5 V
30Ground
31Interrupt Request
32NC
33Address
34NC
35Address
36Address
37Register Select
38Register Select
39NC
40Ground
7If the hard disk drive signals appear as indicated, then the hard disk drive should be replaced. If the signals do not appear, then either the data cable or the CPU board is suspect. J12 of the CPU board can be probed in the same manner as described above to check for the same signals.
8Select Stop, and turn off the mainframe. Remove the power cable and replace the faulty assembly.
9Reassemble the mainframe.
