Fujitsu MAS3367FC, Product/Maintenance Manual

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Diagnostics and Maintenance
6-14 C141-E198
Table 6.2 System-level field troubleshooting
Item Recommended work
DC power level Check that the DC voltage is within the specified range (±5%).
Check that the +5 VDC value (pin of the interface connector) is 4.75 to
5.25 VDC.
Check that the +12 VDC supply (pin of the interface connector of disk
drive) is 11.4 to 12.6 VDC.
Electrical noise Make sure the maximum ripple peak-to-peak value of +5 VDC is within
250 mV and +12 VDC is within 250 mV.
Make sure the high frequency noise (over 20 MHz) is less than
100 mVp-p.
Drive selection address Check that the disk drive selection address is set correctly.
System cables Check that all system cables are connected correctly.
System diagnostic test When possible, execute the system level diagnostic routine as explained
in the host computer manual. This gives a detailed report of a possible
fault.
Intermittent or nonfatal errors Check the AC voltage from the power supply. Check the DC voltage
level at the power connector for the disk drive.
If the AC voltage level is abnormal or there is a lot of electrical noise,
notify the user of the error.
If the DC voltage level is unstable, replace the power supply unit.
If possible, replace the disk drive. If replacing the disk drive does not
eliminate the error, the removed disk drive is probably not faulty. To
continue error analysis, refer to the hardware and software manuals
supplied with the system.