Fujitsu MHV2120AT manual 3 System level and field troubleshooting, Maintenance and Diagnosis

Maintenance and Diagnosis

	Table 1.3 System level and field troubleshooting
Check to be made	Recommended work
DC power voltage	Confirm that the DC power voltage is within ±5% of the standard value.
level	When measured at pins 41, 42 and 43 of the power supply connector, the
	+5 VDC must be 4.75 to 5.25 VDC.
DC power ripple	Check that the maximum ripple at +5 VDC power is less than 100 mV
noise	peak to peak and 200 mV peak to peak respectively.
Power-interface	Confirm that the AT interface cable is properly connected at the disk
cable connection	drive, power supply section, and control unit.
Switch setting	Confirm that the switch on the interface connector at the disk drive
	control PCA is set for normal operation with the host computer. Refer to
	Section 3.4 of the MHV2120AT, MHV2100AT, MHV2080AT, MHV2060AT,
	MHV2040AT Disk Drives Product Manual for switch setting.
System cable	Confirm that all cable connections throughout the system correctly
	connected.
System diagnostic	To further isolate the failure, if it can be done, execute the system level
test	diagnostic routine described in the host computer manual.
Intermittent or	Check the AC voltage level at the power supply section and recheck the
indefinite error	DC voltage level at the disk drive power supply connector.
	If the AC voltage level is abnormal, or if there is a lot of electrical noise,
	notify the user.
	If the DC voltage level is unstable, replace the power supply section.
	If possible, replace the disk drive. If the fault remains, the disk drive is
	not the case. For suggestions to isolate the failure further, refer to the
	hardware and software manuals provided with the system.

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