AMI E-120 mechanism stuck

[d***@hotmail.com]

Have good DDC voltage. When the mechanism is plugged into the junction box, the relay in the box chatters and the mech also makes noise, but doesn't move a bit. It is like it is stuck. Help! Many thanks,
Dave

[John Robertson]

Post by d***@hotmail.com
Have good DDC voltage. When the mechanism is plugged into the junction box, the relay in the box chatters and the mech also makes noise, but doesn't move a bit. It is like it is stuck. Help! Many thanks,
Dave

Is the gripper motor in its home position? If so, can you move the
mechanism if you remove the scan motor and just try to slide the mech
sideways? Might be seized motor or seized mechanism sliders.

Please check that the fuses are still the factory values! Often folks
over-fuse which can lead to fire or (worse) burnt out motors, etc.

Check the DC voltage - should be around 24VDC (32VDC unloaded) - if low
suspect the recitifier. If your Selenium rectifier is damaged (smells
like rotten eggs if damaged) then replace with a silicon bridge
rectifier, BUT be sure to add a 1.5A slo-blo fuse to the AC side of the
rectifier to protect the transformer if the bridge shorts out. Selenium
rectifiers fail open, silicon fail shorted and thus need an AC side fuse.

John :-#)#

[d***@hotmail.com]

Post by d***@hotmail.com
Have good DDC voltage. When the mechanism is plugged into the junction box, the relay in the box chatters and the mech also makes noise, but doesn't move a bit. It is like it is stuck. Help! Many thanks,
Dave

I guess I should have mentioned that the mechanism is stuck in the record-play position.
Dave

[John Robertson]

Post by d***@hotmail.com

Post by d***@hotmail.com
Have good DDC voltage. When the mechanism is plugged into the junction box, the relay in the box chatters and the mech also makes noise, but doesn't move a bit. It is like it is stuck. Help! Many thanks,
Dave

I guess I should have mentioned that the mechanism is stuck in the record-play position.
Dave

Ah, this is usually a problem with the CAM switches. Try cleaning the
contacts and seeing if they are adjusted correctly. Also, take the hatch
cover off the gripper motor and see if the armature is jammed
(indicative of cam switch issue). If jammed, then turn it
counter-clockwise (might be clockwise, sorry, not certain) using a
wooden pick to avoid damaging the windings. It should have blown the
motor 1A fuse, if jammed and if not, then it is way over-fused and you
will possibly have damaged the rectifier.

If you are nervous about poking inside the motor (and you should be!)
loosen the motor mount bolts and slide it out slightly to free it up.
Now you can easily push the armature with your wooden stick and figure
out which way it needs to turn to pick up the record and return it to
the rack.

hope that is clear, I haven't had one of those mechs in the shop for
years so haven't made a video of the problem/cure.

John :-#)#