The mechanism includes a ‘Safety Plunger’, to insure that damage to the record or the mechanism does not occur from a warped record. The Safety Plunger is mounted at the rear of the carriage, on the side facing the record magazine, and is shown in the photo at left. Whilethe record is being transferred back into the magazine, the Safety Plunger is released to move into the area formerly occupied by the record. A warped record will prevent this from happening, so the clutch cannot shift back into scan, resulting in the record being transferred into play again. Another possibility is a worn on poorly-lubricated clutch shifting lever, or a poorly lubricated Detent Arm. The trip and play again sequence will repeat until the obstruction is removed or the power is turned off. Years of inattention, no cleaning and no lubrication will result in what lubrication is left turning into a sticky or solid mass which prevents free movement of the Safety Plunger, duplicating the action of a warped record. A gummed-up clutch shifting lever could also cause this problem. The solution is to disassemble that portion of the mechanism (usually requiring that the magazine be removed to gain access), clean away the ‘gunk’, lubricate and re-adjust whatever was disassembled. If the problem is caused by lack of lubrication of the Detent Arm on its shaft, you will probably have to remove the clutch assembly to gain access. The mechanism Operation and Adjustments manual for your jukebox does a very good job of detailing which adjustments affect others, and which adjustments must be correct before making another. Before attempting to clean up your mechanism, get a copy of this manual. It's available from: Always Jukin', Victory Glass, or Stamann Musicboxen for those in Europe. Before cleaning the mechanism, remove the motor, trip solenoid, cartridge, trip switch, and memory unit. Use a water-based degreaser followed by plenty of fresh water, and make sure it dries completely before doing anything else. Ron Rich's Seeburg Mechanism Guide has a step-by-step procedure that guides you through removing and taking apart the clutch assembly. You should consider getting a copy before attempting clutch disassembly or mechanism degreasing.
If you have a V200, VL200, or older machine, this problem could also be caused by a maladjustment of the clamp arm switch. This switch was provided on those mechanisms to automatically reject when there was no record in the slot. The switch must be adjusted so that both contacts are open when the record is clamped to the turntable.