8-Inch Door Latch Repair

A horizontal ribbon.

I am documenting how I repaired three 8-inch drive door latches. This fix is applicable to Siemens FD-100, FD-120 and FD-200 8-inch disk drives.

Note the position of the door springs and the door lock mechanism on the top of the drive before removing the front panel. The door lock looks like this:

Door Lock

There are door springs on each side on top of the drive. The door springs look like this:

Door Spring

I removed the four cables from the PC board in the drive then I removed the fout Torx screws that help the board. Here is what the board looked like:

Drive PC Board

Once the board was out of the way, I could pull the four Torx screws that held the front panel on the drive. Here is what the front panel mounting looked like:

Front Panel

The door latches were broken where they road on the door latch rod. They would slip off the rod and not unlatch the door. Here is the broken latch:

Bad Latch

Note the two holes drilled in the top of the door latch on each side. I ran some bare #26 copper wire through these holes and pulled the door latch against the door latch rod. Be sure to put the door latch spring in correctly so the door latch will push away from the drive.

Twisted Wires

I twisted the wires to pull the door latch up tight to the door latch rod. Then I soldered the wires to keep them from loosening up and allowing the door latch to again fail.

Good Latch

The door lock mechanism on top of the drive on the right side needs to be in the same position it was when the front panel is attached to the drive. The door springs need to be seated on the pins on the door and in the round indentations on the frame.

Reinstall the front panel with the four Torx screws that held it in place. Reinstall the PC board with the four Torx screws that secured it in place. Reinstall the four plugs on the PC board. Test the door latch with an 8-inch floppy to ensure proper operation.

A horizontal ribbon.

Last Modified: 9 October 2015