[Jim Koehler]

With the BOL on automatic, when the tone arm goes into the reject groove, it will swing a pendulum (really!) that has a fine wire connected to it. This pendulum assy tracks the tone arm travel but is below the motorboard. It also has a contact point at one extreme end. That contactor will swing into that silver plate that will energize the solenoid that starts the reject process. This uses 6 volts AC in this circuit. While the platter is turning, if you watch the operation of the silver plate, you'll see that it moves up and down with a travel of 1/16 to 3/32nd's of an inch. The assy has a small adjustment screw to achieve this motion. This plate is also grounded to the motorboard.  

With me so far?

As the tonearm travels with the record groove, this pendulum will sit still and just travels along. When the needle goes into the reject groove, the momentum of the tone arm upsets the balance of the pendulum and it makes contact with the silver plate thus setting off the reject process. How it does that is this: There is a small circle of a rubber wheel that is cemented to the pendulum. The axle shaft which allows the pendulum to swing is connected to the rubber, with the pendulum.  The rubber wheel itself is traveling directly under the contact plate of course with the pendulum. With the up and down motion of the contact plate and the balance of the pendulum being upset, the rubber wheel comes into contact with the plate and momentarily holds the contact to the plate thus assuring a solid electrical contact to the solenoid coil. This actuates the reject fork to push the reject gear into the driver gear and start the reject process.

This piece of rubber goes hard and loses it's grip. Hence, no auto reject action. 

What to do.....

Since the assy follows the tone arm action, it can be found pretty easily. What comes next will drive you nutz.....  Prop up the motor board (upside down at this point) and lock the tone arm.Look for the small rubber wheel in the assy.  With the most delicate wirecutters you have, break out the old rubber off that's sitting on the pendulum shaft. Make sure you do not disturb the contact arm nor the coiled fine wire on the opposite end of the shaft. Before you do anything, study the job. (look for the wheel, the pendulum with it's contact and the coiled fine wire in that order) Notice how far the wheel extends above the pendulum frame. 
Find a fresh rubber grommet whose outside dimension is 1/4". Take out your micrometer and measure the shaft cross section and you'll find that it's .050". You need to find a grommet that has nearly the same inside hole size. Another way to do this would be to get a piece of 1/8" thick rubber. Then drill a .050" hole in it, center a hole punch over the hole and save the punching. Either the grommet or the punching will work....I've successfully used both methods. 

Here's where it gets a bit tricky....

Using an Exacto knife, make ONE radius cut outwards from the center hole of the grommet. Then dry mount the grommet onto the shaft. Make sure that the grommet extends no more than an 1/8 of an inch above the pendulum frame. (this frame is what the shaft and the pendulum rides in). If everything looks good, cement the grommet, opposite of the frame side with a rubber adhesive to the shaft. I use 3M black weatherstrip adhesive...stock # 08008. And just a small dab will do...do not get sloppy with the application. 

OK...take a breath and let everything sit overnight.

Makes sure the pendulum is swinging freely in it's frame. 
If you noticed, there is an adjustment screw just off of the pendulum assy. This screw will adjust the height to the contact plate. Between that and the contact plate adjustment the reject should come into play. 

Good luck....
...Jim