HDA CHANGE-OVER

TM11-7025-229-12

(3)

Verify that after approximately 30 seconds, the RDY light illuminates.

(4)

Set the UNIT SELECT switch to the correct position. Refer to applicable system manual.

NOTE

If the UNIT SELECT switch is not set to the correct position, the PASS and SEL

indicators will flash.

(5)

When the host computer is loaded and ready to conduct a system test of the disk unit, momentarily

position the SUB SYS TEST toggle switch up.

(6)

Verify that after about 15 seconds, the PASS indicator starts blinking. If the FAIL indicator lights, rerun

the test. If the problem persists, refer to chapter 3 for maintenance instructions.

(7)

For more detailed operating instructions of the disk unit in the specific operating system, refer to the

applicable system manual.

d. Turn Off Procedures. Refer to applicable system manual. Position the PWR ON/PWR OFF toggle switch

to PWR OFF.

2-7.

HDA CHANGE-OVER

Periodically, it will be necessary to exchange Head Disk Assemblies because of system operational requirements. Also,

it is absolutely essential that the HDA be removed from the disk unit prior to installing, removing, or moving the disk unit.

The text to follow provides an illustrated step-by-step procedure for removing and installing the HDA. See illustration on

next page.

WARNING

DO NOT remove the HDA or cabling with the units power on. Position PWR ON/PWR

OFF switch to PWR OFF first.

CAUTION

Great care must be exercised by the Operator when handling the HDA. Avoid subjecting

the HDA to bumping, rough handling, or dropping. Shocks due to improper handling can

cause the heads to score the disk surfaces or crack the heads; a drop of one-half inch

onto a hard surface may cause a head crash.

2-9