Apple PC 5.25 Drive Troubleshooting Guide

Fault-finding for the Apple PC 5.25 Drive and its controller card, from Apple's 1987 Technical Procedures. Apple's diagnostics test the drive and the Apple controller card together, so a fault can be in either, or in the cable or the computer. The take-apart steps are on Apple PC 5.25 Drive General Maintenance.^[1]

What the drive needs

A Macintosh SE with the Macintosh SE-Bus PC Drive Card, or a Macintosh II with the Macintosh II PC Drive Card, or a compatible third-party card. The drive cable plugs into the card's DB-37 connector, at the expansion port on the SE or the back of the Macintosh II.^[1]^[2]
A file transfer program such as Apple File Exchange.^[1]
Double-sided, double-density 5.25-inch disks of at least 48 tracks per inch, formatted for 360K.^[1]^[2]

Apple's diagnostics

Apple tested the drive with MacTest SE or MacTest II. If the system uses a non-Apple controller card, fit an Apple card before testing.^[1]

MacTest SE (known-good Macintosh SE, SE-Bus PC Card and drive, and a test disk):

If the Macintosh SE is not known to be good, run MacTest SE's logic and drive tests first. If MacTest SE will not run with the PC card installed, remove the card and retest; if everything passes without the card, replace the card.
With the power off, fit the card and connect the drive.
Start up from the MacTest SE disk in drive one, choose Test Selections from the Options menu and select the Apple PC 5.25 Drive test.
Insert a 5.25-inch disk in the PC drive. The test formats it, so any data on it is lost.
Click Start.

MacTest II follows the same pattern on a Macintosh II: run the logic, drive and video card tests if the machine is not known to be good, fit the card and drive with the power off, wearing a grounded wrist strap, note the PC card's slot number from the Configuration item on the Options menu, select the Apple PC 5.25 Drive test, enter the slot number beside it and start the test. Do not open the drive door during testing; it can damage the disk and hang the Macintosh.^[1]

Apple notes that the test cannot always tell which module failed. If it reports that the drive or card is bad, replace one module at a time following the flowchart.^[1]

Apple's troubleshooting flowchart

Test the drive and controller card with the diagnostics above, repeating the test several times if the fault is intermittent. If they pass, the drive and card are working. If not, try these in order, testing after each and refitting the original part before moving on:^[1]

Exchange the drive mechanical assembly.
Exchange the controller card.
On a Macintosh SE, exchange the controller card cable.
Exchange the computer's main logic board.

Other checks

Never fit more than one Macintosh II PC Card in a Macintosh II: Apple warns that the power supply was not designed for two and could be damaged.^[1]
The drive takes +12 V and +5 V from the computer through its cable. Check the cable's power connector at J2 and the bus connector at J1 on the mechanism, and the ground strap screw on the shield case.^[3]^[1]
For head and mechanism faults common to 5.25-inch drives, see Floppy Drive Repair.

Related pages

References

↑ ^1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 Apple Computer, Apple PC 5.25 Drive Technical Procedures (1987), hosted as File:Apple PC 5.25 Drive Technical Procedures (1987).pdf. Basics 1.2; Diagnostics 3.1-3.5 (MacTest SE, MacTest II); Troubleshooting 4.1-4.3 (flowchart and notes).
↑ ^2.0 ^2.1 Apple Computer, Apple PC 5.25 Drive data sheet, M2242/A, June 1988, system requirements, hosted as File:Apple PC 5.25 Drive Data Sheet (1988).pdf.
↑ Apple Computer, Apple PC 5.25 Drive Service Source, Specifications and Take Apart (PDF pp. 3-7, 11-15), hosted as File:Apple pc 5.25 drive.pdf.

[tp-1] 1.00 ^1.01 ^1.02 ^1.03 ^1.04 ^1.05 ^1.06 ^1.07 ^1.08 ^1.09 Apple Computer, Apple PC 5.25 Drive Technical Procedures (1987), hosted as File:Apple PC 5.25 Drive Technical Procedures (1987).pdf. Basics 1.2; Diagnostics 3.1-3.5 (MacTest SE, MacTest II); Troubleshooting 4.1-4.3 (flowchart and notes).

[ds-2] 2.0 ^2.1 Apple Computer, Apple PC 5.25 Drive data sheet, M2242/A, June 1988, system requirements, hosted as File:Apple PC 5.25 Drive Data Sheet (1988).pdf.

[ss-3] Apple Computer, Apple PC 5.25 Drive Service Source, Specifications and Take Apart (PDF pp. 3-7, 11-15), hosted as File:Apple pc 5.25 drive.pdf.

[1]

[2]

[3]