Rock-ola 488 failure in Sequence 14

I just acquired a Rock-ola 488. Everything seems to function properly up to sequence 14. The gripper bow transfers the record almost to the turntable, but the gripper stops just short . By "cycling and observing" I've seen that the gripper's travel stops when microswitch 2 dips into the first recess in it's path.

At rest , with the gripper in home position, microswitch 1 is in it's cam detent and fully open (against the left shoulder of the dip, looking from the back of the juke). I can manually rotate the magazine motor the the extent of it's travel, then forward the tone arm to make contact with the cancel switch, but sequence 17 does not initiate.

Likewise, when it is in the state of the gripper being stopped short, I can manual engage microswitch 2 and the record transfer to the TT will complete. Also, when the music cycle ends, and the cancel switch should engage the reverse relay, I can engage microswict 2 once again until it reaches the raised part of the cam, then the return cycle completes.

I still too fuzzy on the complete sequencing of this juke, even having the service manual, to troubleshoot by myself. I'm wondering if a N/O-N/C state of the microswitches can negate seqeunce 17.

Thanks in Advance for Any Help,
Aschylus

Hi
Micro switch 2 should slow down the process so that the record is placed slowly on the turntable and the tonearm is placed slowly on the record, all controlled by the mechanism control board at the back of the chassis, are all fuses ok and anything burnt out on this board.
Sequence 17 should operate the reverse relay on this pcb, check for any loose connections,
Could also be a gripper motor problem?
regards
clones

Turns out it was the .5 amp slow blow fuse on the mechanism power board. I wrongly assumed that the entire mech power board would be inoperable if that fuse was blown. Quick and easy (and cheap) fix. My 488 started running too slow after I got it up and going. The TT motor grommets had compressed causing the motor to drop and the idler wheel was getting drive from the upper, thinner part of the motor shaft. Perhaps this motor has a thinner part for 33rpm's as well as 45. Got the grommets cheap from here:

http://www.tubesandmore.com/products/P-R407

I've done a lot of business with them in the past working on radios. Anyway, doesn't seem to be any additional problems with this juke. Time to rock!

What color are those grommets ?
Ron Rich

The original grommets in the 488 were white, aged yellow. The ones in the link I provided are black. I considered placing an extra washer or two between the grommet and the C-clip to compensate, because I'm kind of impatient like that when I have a new toy, but had overcome my enthusiasm and waited for the parts.

OK--but I have never been ale to use other then the "white" ones, without having a "hum problem"
Hope your luck is better--the correct ones are available--. Ron Rich

That's interesting. Do you think hum is caused by EMI or a density or conductivity property between the different rubbers? Perhaps a less dense grommet would transmit vibrations to the cartridge cause hum.

Beats me. I'm just trying to learn. Let's hear some theories on this.

I believe it is due to transmission of "motor noise" thru the grommets. The white ones are much "softer", therefore they "cushion better. RockOla used two different "mounting systems" for the motor. Some models are secured with a screw and an eyelet, others are done with just a post, and "E ring"( or for the guy's across the pond "Circlip"). If using the 1st type, the eyelet MUST be used--caution-- it "falls out" and gets "lost" easily ! Ron Rich