440 Jukebox Repair Journal
By Chad Hauris, Retro Electronics and Audio Lab,
Midland, TX. 2/27/07
Rockola had the typical Rockola problem...gummy grease in the mechanism.
The gripper and gears were degreased with Gumout followed up with
Con-tak cleaner and then relubricated with Zoom Spout oil. The write-in
carriage was stuck...the write-in motor needed to be cleaned and
re-lubricated, plus some oil needed to be applied to the write-in track
After getting the mechanism to work, selection performance was still
poor. A selection would be entered from the keyboard and the write-in
carriage would just spin without selecting. This was fixed by spraying
the contacts with Deoxit and passing a lint-free cloth under the
The contact circuit board was also sprayed with Deoxit and polished.
All of the speakers were bad, so 2 new woofers and 2 new tweeters were
installed. Also 3 new fluorescent ballasts were installed, along with a
new silicon rectifier and power cord. The amp had its capacitors
checked and ESR was found to be good.
Front view of completed cabinet.
We had to call Able Locksmith to get the woofer panel open as the
original key was lost. The locksmith did a very good job of opening the
lock and making a new key, and also repaired the coin box lock.
The locksmith's van is completely equipped as a workshop.
Able Locksmith did a great job and we would highly recommend them.
Rockola mechanism before repairs.
Mechanism on the service table.
Cleaning out the cabinet.
Carousel area. The carousel drive gear contains two grooves which
activate the mechanism which determines if an A or B side will be
played. On one revolution of the carousel, the lever rides in the B
side groove and flips the pivot mechanism for the gripper to play the
reverse side of the record. Also, a switch is activated so that only
activated memory pins corresponding to B side records will stop the
The next revolution, the lever slips through a passageway into another
groove in the gear which positions the gripper pivot and switching
system for "A" side play.
This contrasts with the similar Rowe mechanism which uses a solenoid to
determine "A" or "B" side play and can play both sides of a record in
sequence, whereas the Rockola cannot. The Rockola mechanism will first
play all "A" sides selected and then all "B" sides.
This mechanism relies on metal-to-metal contact of a smooth metal cam
riding in the grooves and is very prone to getting bound up by gummy
lubrication, resulting in no carousel motion. On this unit, this
mechanism was extremely gummed up and was thoroughly cleaned with
Gumout and relubricated.
Cleaning and lubricating the write-in motor.
Power supply before repairs.
Power supply after repairs. A new power cord and silicon rectifiers
Testing the Rockola mechanism.
Installing new woofers. Both old woofers had woofer foam degradation.
New tweeters: one is a Quam exact replacement size midrange, and we
were able to adapt a Radio Shack tweeter in for the other one. Both old
tweeters had open voice coils.
Testing the fluorescent lamps.
Re-installing the records.
John polishing the 440.
More photos to come!
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