The FD1157C is a 5.25“ double sided high density floppy drive made by NEC. It uses a metal belt mechanism to facilitate head movement and locks the disk with a lever. Head loading is done with a solenoid.

It uses the G9ZHF control board and the FDM-530BQ, GFS-505 or DR-9324 motor board.

g9zhf.pdf

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Over time the foam the adheres the head cover to the head assembly degrades and the head cover will fall off. While not being critical it is recommended to fix this issue.

The Head cover repair can be performed by following these steps:

1. Clean the head cover and the head assembly of any remaining glue and foam as best as possible.
2. Cut out a small rectangle of neoprene sealing tape.
3. Glue the rectangle to the head cover with the adhesive side facing up.
4. Let the glue dry completely.
5. Attach the head cover to the head assembly using the adhesive side.

Not all drives will be able to seek 84 tracks without some moderate modification.

The modification can be performed by following these steps:

1. Unscrew the end stop screw on the stepper motor until it no longer protrudes out the other side.
2. Re-align the tracks with a front bias, make sure that track 83 can be reached.