Pentax MX Main PCB Removal

Remove the lever cap. The cap is reverse threaded.

Lift off the advance lever.

Remove the collar beneath the lever.

Set the ISO to 100 and the shutter speed to 1000.

Remove one pin head screw.

Lift off shutter speed dial.

Remove the collar beneath the dial.

Installation Notes: Make sure that the tab on the shutter speed resistor mates properly with this slot on the shutter speed dial.

Place a tool in the fork of the rewind shaft. Turn the rewind knob counterclockwise to loosen it.

Remove the lock ring underneath the rewind knob.

Remove the cover plate.

Remove two M1.7 x 3.2 mm screws.

Remove two M1.7 x 2 mm countersunk screws.

Lift off top cover.

The release cable pin in the shutter button is loose and may fall out.

Unsolder one blue wire for the LED switch.

Unsolder one green wire for the motor drive.

Unsolder two yellow wires for the aperture resistor.

Unsolder two brown wires for the shutter speed resistor.

Unsolder one gray wire for flash sync.

Remove one M1.4 x 2.8 mm screw and washer.

Remove one M1.7 x 2.8 mm screw.

Pull the LED PCB out of the side of the mirror box.

Remove two screws.

Lift of flash sync connector.

Remove one screw.

Remove light cell PCB clamp

Slide the light cell PCB up and off the eye piece.

Use isopropyl alcohol to loosen the adhesive attaching the PCB to the prism.

Use a soft, thin tool to separate the PCB.

Lift off the PCB once it is free from the adhesive.