Reassembling the Capstan motor of an AKAI VCR model VS-555

The video drum of VCRs is spun about by a Capstan motor.

Our old AKAI VCR needed a new Capstan motor control PCB (printed circuit board), so we bought a second-hand motor PCB on the internet and installed it in our VCR.

Top view of Capstan motor drive PCB	Bottom view of Capstan motor drive PCB

We figured the motor magnet was homogenous and thus it didn't matter which way the video drum and magnet were oriented when we screwed them back together, since they both rotate anyway. Boy, were we wrong!

When we had reassembled it the first time, it was able to play tapes, but the picture was split at the wrong place on the screen and showed a layer of gray noise at the split, as shown below.

Correct picture.	Picture with drum/motor/magnet misaligned.

Turns out, you have to hold the video drum in the correct orientation to the VCR chassis when you fasten in the new Capstan motor PCB & magnet and put all the other rotating parts together.

Since we hadn't observed the correct orientation when we took apart the VCR, we had to correct by trial and error (reassembling several times with minor adjustments til we had the picture right. What follows is my attempt to describe the correct orientation, for the benefit of others who own this type of VCR.

If you have a different type of VCR but you're getting the same error with the split screen, you might want to try reorienting your video head, too. Some VCR makers are kind enough to provide alignment arrows.

	For these pictures, "North" is the face of the VCR where you put the tapes in.
1) Turn and hold the drum into this position relative to the little arm (in effect, to the VCR chassis, since the little arm is fixed relative to the chassis). Be careful not to touch the video heads.	Top View of VCR Capstan motor PCB assembly
	2) NOW VIEW VCR's OPPOSITE SIDE (i.e., the bottom). It might help to hold the VCR up on its face, so you and a friend can access the top and bottom sides of the VCR simultaneously. Make sure you're still holding the video drum fixed with respect to the chassis.
3) And at the same time, orient the shaft collar into the position shown, relative to the motor PCB (in effect, to the VCR chassis). Screw it down with the Allen screw. You can release the drum now.	Bottom view of VCR capstan motor assembly. Notice the change in "North" for this picture.
	4) Orient the Magnet so the 3rd hole on the magnet is opposite the allen screw on the shaft collar. Screw the magnet on.

To reiterate, if you don't have an AKAI 555, your VCR's video drum will look different than ours, but at least you can try reorienting your capstan motor + magnet + video drum stack if you are getting the split screen effect after reassembly. Good luck!