ROWE R-74 keeps ejecting

Each time a record is selected the arm just hits the record and it rejects it . It plays once & a great while . I have removed the record mech and gone over , cleaned & tested every contact , switch and relay . I also unhooked all 3 eject devices . Still ejects .

en,
If it's "ejecting" records may I have them to use as Frisbee's for my dog ?? If it's REjecting them, are all of the reject switchs open--and the "no record reject switch" also must remain open. Check with meter--if all's well, have you oiled the gripper motor-armature MAY be "coasting"--or the switch is not opening that stops the motor-- Ron Rich

The last line in my post said i unhooked all 3 Eject devices . Where is the no record reject switch ? and which one is the motor stop switch ? a figure its on the left side around that cam .

And bring your dog . The owners records should be eaten .

I'm going to second one of Ron's suggestions here; this is a typical example of a bone-dry gripper motor whose rotor has become glazed and won't snap back instant;y when power is cut.

Carefully loosen one lug from the motor coil. make selection and when the mech stops st a slot touch the slid-on connector back onto the correct lug on the motor coil. The gears should start and stop -instantly- no coasting. If it coasts it simple runs past the stopping point established by a microswitch on the cam. Light oil may help here -for a time, in my own experience, once this happens the motor will have to be replaced.

That microswitch and it's adjustment is another place to check.

I don't have the R74 manual, but there are only about 3 micros actually involved in mech operation. The one with insulated lugs is the T-T motor. Rowe specifies that the switch should change mode on the middle step at each cam profile. It should be easy to find the one that shuts off the gripper motor (it also unmutes the amp).

Rob/NYC

Hi Ken g,

The fault could be down to Mechanism Control relay that may have gone faulty if you have removed all four means of rejecting the a record, rear of cabinet reject button, canel switch on mecanism, reedswitch cut off and auto cut off for warped or missing records. I have seen the links on this relay that the insulation has burnt and shorted out contacts, the transfer motor n/o contact on pins 7 & 11 of the relay, this is the only switch in the transfer motor circuit, if it is shorted it will keep cycling for ever or untill it over heats.

Please let us know how you get on.

Regards
Alan

Alan Hood
ami-man
UK

Hi Rob,
10 wt. oil will not get it--I have seen "a million" of that type of motor, that have gone dry--a drop of 20 wt, on both sides of the armature shaft, and a total re-filling of the (large) oil wicks, will have it operating perfectly till, it "runs dry", again-- Ron Rich

Ok , i will service the motor . I have also restored several of these mechs in different models and have not run into this . Strange how these jukeboxes lately are playing hard ball on me !

I usually just restore each part of the darn thing so its all done right . This ROWE 74 is so ugly its almost not worth the time and the LPC about the same .... so i am trying to avoid total restore on these .

Glad you guys are here .

Ok i removed the mech and set it on the bench . Oiled all 3 motors . Put it back in the machine . First thing it did after selecting A-1 is the motor that turns the contacts just kept spinning . I kept releasing and punching A-1 and it finally selected .

Still rejects all selections . Getting closer to the fire pit

STILL NEED suggestions !!! Please

Ken, the keyboard selection issue and the rejecting are completely separate -except that both point to old-dirty assemblies.

On the rejecting, did you disconnect one lead to the gripper motor while it was operating and note coasting? Again, there must be none. Did you look for and examine the microswitch on the cam that activate to shut the gripper when a record is set?

I have not seen an R-74 since the late 80's but I do recall a number of diodes in the mechanism near the relay and cam switch. I copied-retrofitted this design onto an MM-1 mech to eliminate some switches. You'll need to test the diodes. However, I still think this is simply a bad gripper motor's slip clutch failing to disengage and causing the motor to coast.

Rob

Ok here is what i have come up with after reading all the posts .

The gripper motor is working 100% . I put the mech up on the bench and hooked it to a power supply and watched it several times and it comes to an instant stop every time . As soon as the motors voltage is cut the core slides over and its shaft stops dead .

I took that small circuit board out and checked all the diodes and other parts on it . No bad parts .

This thing still rejects ( or ejects for Ron ) the records before it can play it . I saw this thing work 3 times out of 50 or so .

Next i put the mech back into the jukebox moved forward so i could get to things better . I had one wire off of the gripper motor , then i started the machine and touched the wire back to the motor till it reached the exact point the needle sits on the record and then pulled the wire away to stop the motor .
I hooked a voltmeter to the motor wires and got 29 volts AC . I then started to poke & probe around all the micro switches and any other thing o could think of to try to find what was kkeeping voltage on that motor .

The only thing that will remove the voltage from the motor is to push a micro switch up on the right side top of the mech for a second . This switch has a plastic arm next to it . Also when i push it , the center of the turntables 45 adaptor drops down , let go and it pops back up . During the pushing in & out of this switch the voltage stays away from the motor
If i back the gripper motor up by hand by moving its gears just enough to make it release the 2 last micro switches it is supposed to stop on and put it back in the play position the voltage on the motor returns .
If a watch the switch & plastic arm during a normal cycle , it moves as normal . There is no binding or anything and it appears to be working like it should .

Still stuck .... sounds hopeless ? maybe someone moved a wire to the wrong place somewhere in this ?

By any chance, are the 'no record" reject wires still connected to the tonearm assembly? I always eliminate those.

On the MM series the 45rpm spindle pops up as the cam starts to turn ans only fall down if a small hole record hits the trip wire or the cam returns to home position. tr disconnecting both wires from that coil. That is another item that I've always eliminated if it wasn't already modded.

At this point if I had not solved it yet, I would connect a 28v lamp to the gripper motor terminals and see if, in fact, the voltage is ever cut, even for a fraction of a second from the gripper motor.

Take a look at the relay on the side of the mech. Does it pull-in when the gripper motor is energized? If so that opens the possibility of residual magnetism holding it past the stop.

The latest schematics I have for that mech is MM-2 -that has always been enough to fix the entire 1100 series. I'll pull those an see what else i can think of. I recall something like this happening due to a bad micro on the sprag assembly.

Rob

Ken,
I don't have a schematic--but doesn't that motor have AC all the times--my thinking is that it is supplied with a "ground", in order to operate ?? Ron Rich

I have done all of that but instead of a lightbulb i used my voltmeter . I replaced the mech relay twice with other good ones .

Now today i was working on it a bit . I was making selections so i could look at my voltmeter . The voltage never dropped during the gripper motor , only quit when the gripper was back over the rack .

After 5 or 6 of these cycles the motor stopped where it should and played . Now all by itself it wont eject . Pushing any eject button causes the relay on the amp to click . The only way to get it to eject now is to move the gripper gears ahead slightly . I took the 2 micro switches loose ( the front 2 ) that the cam lands on during play and adjusted them at several angles with no luck .

This thing has a mind of its own . What will it do tomorrow ?

Ken, what you are now describing is a classic case of failing microswitch(s). There only three actually involved with the robotics, There is also one on the sprag assembly. I'd replace them. A DVM is not the best way to test snap-type switches as most meters won't respond fast enough. A cheap low-ohm-per volt analog meter is good, or just a bulb-battery. The switch must be decisive. When it snaps it must be on-off and there should not be readings bouncing as the plunger is depressed.

Rob