Phonoland

Hey, I have a 480 that boots up fine, amp works, etc.. but the pick up arm always rests in the turntable position and won't reverse. If I manually turn the arm motor back a bit, it'll drop back down when powered up.. Also, the arm doesn't squeeze in and out, and if I turn the motor backwards by hand it will flop about if it comes off of the guide that holds it straight when resting on the turntable.

Upon power up it'll scan the records through to the home position and stop. It'll accept selections as well, but just scans back to home and stops.

If a video will help I can make one. I have parts & service manuals but they seem fairly useless so far.. this thing was dead when I got it and had a bad tantalum cap on the power supply PCB that was causing the 9.6v to go up to nearly 14v, and the manuals had no "straight" schems for the supply (and didn't cover 9.6v reg at all) nor a standard wiring diagram.

Just a WAG--someone has reversed the wires on the cam switch that "reports" the gripper position to the computer?--Ron Rich

right on ron.. it looks like the #1 switch was replaced as it's different than the rest of the switches. swapping the wires around seems to have done the trick.

enter a selection and it tries to return the arm back to home, but it jams up soon after lifting out of the resting position as seen in the pic below.. obviously I power it down as soon as this happens and back the motor off..

The arm seems to just free wheel around.. is it supposed to "lock" into those 2 pins on the end? end casting possibly damaged? I've never poked around a rock-ola so I wouldn't know otherwise..

It looks as if there is a whole "bunch of dried grease" in and around that arm assembly. Rocks are famous for "binding up" if not oiled every so often.
Check that the springs in the center are free--and be sure to oil in between the two gears on the end--they MUST slip by one another--Yes, enough "pressure" will "snap off" the pin in the rear !! "Work" the oil in by hand. Ron Rich