Rockola 451 on strike

Hi. I'm new to this forum so please be gentle.
I live on Alderney in the British Channel Islands. Population 1600 (on a good day) and no-one with Jukebox knowledge, so I'm hoping someone on this forum can point me in the right direction.
I've had a Rockola 451 for over 25 years. About 8 years ago it stopped playing records, though the scanner still worked. After looking online I gave the working parts, particularly gears, a good dose of WD40 and hey presto! - everything was fine. Sadly It's now decided to pretty well stop everything. The coin part works and pushing the buttons starts the wheel on the left whizzing round, though the button lights do not light up. The whizzing stops with a click (as it always used to when working) but then nothing else happens. The next stage used to be on the left hand side (record magazine) which would rotate until the correct record was in position, the gripper arm would do its thing (after lubrication) and everything was fine.
If I try the scanner lever nothing happens. No lights come on apart from the fluorescent tube, and there's no discernible sound from the speakers. I've tested lots of fuses, including the ones in the various boxes, and they all seem fine - though there could be others I haven't found.
I've got the manuals, but they're written for someone with more knowledge than me.
We're holding a party in 4 weeks time, and I'd love to get it working again. It sounds awesome when it's going properly.
Can anybody give me some advice?

Cheers

Dave

Hi Dave,
I'll attempt gentleness, although that's not my nature ! ( Read Attn Newbies, above).
Examine the gripper portion--the one you used WD 40 on--( which IMHO is an awful thing to do--being gentle enough ??)
With the power off, find the gripper motor and turn the shaft at the rear of the motor one full cycle, if you can. While doing this, I suggest you oil EVERY thing that moves (if it will) with 20 wt. ND oil. I suspect, from what you have written, that the gripper is jammed --again--
Once free, turn it so the gripper bow is fully over the record basket, then try to power it up, and see what happens--I don't recall if that model is equipped with a fuse, or circuit breaker for the "mechanism", but I would assume whichever is blown--
HTH Ron Rich

Hi
Does the write in arm strike a selection lever into position?, if not the wobble plate slip rings may need to be cleaned with isopropyl alcohol, is it the same for A and B sides? try manually pushing a selection lever into the play position and see if this starts the read out arm and selection process. The other possibility is that the wobble plate solenoid and copper helper spring may need adjustment, when machine is on standby actuate it and see if the play control relay operates. Other possibilities include the current limiting lamp in its socket, or perhaps the scan run off switch is at off position
clones

Amazing! 2 replies within hours of my posting. Thank you so much.
Sadly nothing has worked yet, but I'm hoping this is a process of elimination.
Detailed answers to the suggestions:-
... I suspect........ the gripper is jammed --again-- :- I went through the gripper arm cycle by turning the motor shaft - and have got the blister on my thumb to prove it! It didn't seem to be stuck at any point. (until it got to the end, when the gripper was in position over the record magazine, then I could not turn the motor any more in that direction). Sadly, on powering up again, nothing happened.
Does the write in arm strike a selection lever into position? :- Yes, for both A and B sides
try manually pushing a selection lever into the play position and see if this starts the read out arm and selection process :- Nothing happened
when machine is on standby actuate (the wobble plate solenoid) and see if the play control relay operates :- Still dead as a Dodo
current limiting lamp in its socket :- This lights up at the same time as the loud click - then nothing happens
scan run off switch is at off position :- It's at the operate position when I'm attempting to get it going, and nothing happens when I move it to the scan position.

I'd love to think it was as simple as I fuse, but have tested all I can see. The only strange thing is the fuse visible at the back (more or less in the middle) when you take the back plate off. This reads at 6 ohms, not zero as all the other fuses read.

Any other thoughts very welcome.

Thanks

The Trouble Shooting Guide suggests resetting the Mech circuit breaker. There are two red posts sticking out of the power supply box, one labelled "select sys" and the other labelled "Mech". Half a second after pressing the "Mech" post there is a click from inside the box. There is a quieter click as I release the post. None of which makes any difference to anything. Doing the same with the "Select Sys" post does nothing at all. Interestingly the labels to these posts are the other way round from those shown in the Trouble Shooting Guide.

Probably a complete red herring, but I thought I should mention it. (are smilies OK?)

If you are reading "6 ohms" on a fuse--it IS BAD ! Depending on several facts--how good your meter is--how well it's "zero-ed", the type of fuse, No fuse that's good will read over a few tenths when checked .
If you hear a "click sound" from a CB when pushing it, it means that it was tripped. If you hear a click from it a few seconds after re-setting it, it means that there is a problem in that circuit, and it has re-tripped.
If you are getting "blisters" on your fingers turning the gripper motor, yes--lubrication is needed !! --this MAY draw enough to trip the CB--
Ron Rich

Hi
If not moving at the scan position may be a problem with the play control relay circuit or dirty slip rinds or contacts and its always possible there could be a loose plug connection specifically at the control box under the chassis. Change the fuse and see what happens. If the gripper moves freely from position over the basket to the turntable and back again its probably free enough not to trip anything, when you get it back over the basket it should not move any further hence it will jam as in other rockolas
clones

It's also possible that a MicroSwitch has failed--see post above on how to check them--
Ron Rich

OK. Have replaced the suspect fuse (stuff takes a few days to get here from UK mainland). Sadly, no difference. I think the main clue may be the mechanical circuit breaker which is immediately tripping out. The troubleshooting manual suggests testing some microswitches/ relays. Lacking confidence to do that myself, I'll try and find someone on the island who will give it a go. Will keep you posted.

Well, I've done my usual winter in New Zealand (their summer) and am back looking at my non-working jukebox. Last week I had a friend check the voltages at the microswitches (reading zero) while I was moving the scan lever from "scan" to "operate". He was poking around the switches with his meter when suddenly everything sprang into life !! ?? !! The jukebox then worked perfectly normally for about an hour and wife and I were celebrating by dancing to ZZ Top (we're both late 60's so "dancing" is probably the wrong word). Then, mid record, it stopped again and is now sitting there looking at me, defying me to work out how this happened. Everything is back as it was before the sudden burst into life.
I re-examined all the connections around the microswitches and they seem to be fine. Could it be that the record motor, though seemingly working perfectly and at the right speed, needs lubricating? Would that keep the Mech Circuit Breaker off?

Hi
I would say that when the microswitches were being tested and the machine came back to life there may be a faulty micro switch or fault in wiring/plug connection from micro switch no 3 to control box under the chassis, check that the resistors in the control box are in tolerance, also change micro switch no 3 and reset gripper arm manually back to standby position
clones

Dave,
If the turntable motor quit, mid selection, I would assume that the motor either failed (lack of PROPER oil, is the main reason for this), or it has lost power. If you move the tone arm into the "reject area", what happens ? Look at the schematic--I doubt the play motor is fused separately--but it MAY have a heat sensor in it, that shuts down the motor, if over heated ? Ron Rich

Hi ....... again
Been through the silly season (Alderney is a holiday island so lots of visitors to look after) so went back to look at the jukebox again. As usual, not working until, after moving it to open it up it started working! I left the power on for 3 weeks, testing it each day with no problem. Then showing off to visitors at the weekend it played fine for a couple of hours then stopped mid record for a few seconds, started again for 10 seconds, then stopped .......... permanently. I think it must be a loose connection or a dodgy microswitch, but I've tested what I can (very nervously - don't want to make thinks worse). So I'll now see if I can find an expert on one of the other Islands (Guernsey or Jersey) and see if they have any more luck. Will update if anything happens.

Hi Dave,
Best do this quickly, if you want to update us here ! Read above--forum ends in 6 days !
Ron Rich

Hi
Have you checked the can where the microswitches are located , sometimes it can get loose, is only held in with two small grub screws(i think thats what they are called)
Clones