Rock ola 484 problems

Just got a rock ola 484. While I'm no electronics pro, I have some experience and mechanical as well. I have a service manual. The unit lights up and the turntable is spinning, but the needle arm won't drop. It has a .5 amp fuse on the Mechanism control board that was blown. I replaced it with like fuse and it blew instantly. Can anyone give me some advice as where to start. Please talk in lay men's terms as I'm not a pro and first time posting. I really enjoy the older things and want to preserve history. Thanks in advance.....

Clueless in Missouri.

Hi Clueless,
Welcome !
As written above in "Attn Newbies", (which I hope you read), we are all clueless at one time or another--
If you do not have a Service manual Package (which in RockOla terms, includes a schematic sheet), you will probably remain "clueless". (Also see above for where to get it). I suspect a motor problem--either just dirty and or gummed, up is what is causing the fuse to blow, however, I question if that fuse is the correct size--I don't recall RO ever using a .5 fuse in that circuit--could well be wrong, as a 484 is newer then most I have worked on--Ron Rich

I do have the manual. I also thought it was awfully small, but after double checking, it is what is called for. Yes I read the newbies section. Any game plan for me? I'm not very good at wiring schematics, but from what I have read on here, I am going to unplug the magazine motor and the gripper motor and check to see if it still blows.

Ok, I unplugged both. The fuse blew on the gripper motor. I removed the motor, cleaned it up a bit and reinstalled it. When I had motor removed, I moved the gripper arm freely. I put the arm over the records. When powered up It goes over the turn table comes down, then blows fuse. I repeated this a couple of times. Any ideas? Is there something that lets the gripper motor know the arm has reached it's limit? Or is there something I'm missing? Anyone?

Hi
If the mechamism control board is blowing a fuse, there may be something faulty on that board. Also the microswitches on the cam shaft behind the tone arm assembly would send the various signals to the control board, to slow the gripper arm down beofre it sets the record down and advance the tone arm to the record, i would check microswitch 2 and 2A
regards
Sean

I am still wondering about that fuse size--seems to me that they used a larger value in the motor circuit ??
My recollection is that it was a 1.6 SB fuse, BUT, check this first, BEFORE, trying the larger size--!!
Ron Rich

Yes it is a .5 amp fuse. I checked the microswitches using cont. Tester. It toned out as I opened the switch. So that means the switches are ok. I'm going to try to adjust the switches as the manual states. If that fails I guess I'm gonna try to hunt for a board. If anybody knows of a good complete one please let me know!!

Hate to tell you this--a "digital" meter will not "check" switches--an analog meter must be used.
Ron Rich

I was unaware of that. I was checking continuity. I'm unsure as to why a digital meter will not work for this? I think I have an old baker analog tester around.

They will check "continuity", however checking that does not indicate, one way, or another, if the switch "makes" well enough to carry the required current. Ron Rich

Hi
try cycling the gripper by hand, you just need to loosen motor(3 hex bolts) and see if that blows the fuse, only reason why i suggest this is that a number of rockola's i have dealt with had faulty gripper motors and when they got to the stage of the tone arm advancing and setting down on the record they stopped at that stage. When you are cycling it by hand you should be able to see the motor slow down as the record is brought onto the turntable, on previous machines i had the motor would just stop at this stage giving the impression that the microswitches would be at fault
regards
clones

I'm still "stuck on the fuse size"--just can not see a.5 amp as being large enough for a 24vDC motor fuse !
What are you basing this on--is there a marking near the fuse holder--or do you have it on the schematic ?
Ron Rich

The fuse that is blowing is listed on the Mech Control board as a .5 amp 125 250 volt slo blo fuse. It is also shown on the schematic as such. Maybe I should have stated that it is the fuse that blows, rather than saying it is the gripper motor fuse. But with that said when I unplug the gripper motor it does not blow. I enjoy a good challenge, but I'm getting into territory that may be above the scope of my knowledge. I will say I'm learning a lot, and meeting some great people in the juke business. Lots of people are wanting to help and get great pleasure in keeping the older things going. I must say I enjoy taking something on the verge of going to the dump and trying to resurrect it.

Interesting--traditionally, on many earlier models, RO used a 1.6 amp fuse on the 28 volt line that fused all of the system--including the gripper and basket motors. That fuse became a (poorly designed) circuit breaker in later models, which I have seen replaced by a fuse, many times----?? Got me-- Hope you find it, and PLEASE post it !! Ron Rich

Update! So it was not just one smoking gun. It had a few issues. So the tone arm not coming over and advancing, was because during some kind of move the detents that ride on the cam had jumped over and it mechanically could nit move. I repositioned it and ok. Now the fuse blowing was because the gripper mechanism was gummy. I cleaned and lubricated and seems to be getting better. I think some more playtime and it will work itself out. The A2 microswitch was also out just a bit. The screw had backed out and it was flopping a little. Retightened and seems fine now. It was nice to hear music cone from the old girl again. A big thanks to all who offered expert advice and suggestions. I'm sure I would not have fixed it without this forum and the people who took their time to help an up and comer. I really learned a lot and look forward to trying to save another. One more question. When song is over and gripper goes to pick up and replace in magazine. The gripper arm on the outside is missing the record. I looked for an adjustment and could not find one. I also did not find troubleshooting for this in the book. Any suggestions?