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LPC 480 Won't Play B-sides

Posted: Thu Aug 29, 2013 7:37 am
by Bob B
New member here. I recently purchased a Seeburg LPC480. It worked fine for the first few days, then began occasionally failing to play B-sides as the turntable would reverse its rotation shortly after the needle made contact with the record. Now it happens every time with every selected B-side. The turntable starts out rotating in the correct direction, then reverses itself and of course will not play the record.

I'm no mechanic, but I intend to get in touch with the one who serviced this machine for its previous owner. I'm more curious than anything else and I thought maybe I could get some information here so that I could point the mechanic in the right direction when he comes to service the jukebox.

Here's a link to a video I uploaded to YouTube which shows the problem. Any assistance would be appreciated.

http://youtu.be/HF_3tc5dKe8

Re: LPC 480 Won't Play B-sides

Posted: Thu Aug 29, 2013 5:44 pm
by Rob-NYC
Bob, the LPC is more complex than regular machines of this era. the reversing of the mech motor is controlled by the relay on the front of the mech.

That relay is electrically operated but mechanically held. There are contacts on the vertical cam switch stack and a mechanical linkage on the relay itself.

I scanned-in the original schematics and diagrams but due to this site's embargo on even things that are NOT copyrighted, you'll have to send me a Personal Message and I'll send you the links.

It is a simple problem confined to the mech itself, this should be what your tech will need.

Rob/NYC

Re: LPC 480 Won't Play B-sides

Posted: Thu Aug 29, 2013 6:07 pm
by Bob B
PM sent. Thanks Rob.

Re: LPC 480 Won't Play B-sides

Posted: Wed Sep 25, 2013 7:44 am
by Bob B
The tech I contacted lives about 2 hours away and wants as much information in advance as possible, so he has a better idea as to what he's dealing with when he gets out here. That might be a good while from now as he has a regular job, family, etc. We haven't even scheduled a date / time yet.

In the mean time he asked me to show him, in 2 separate videos, the action of the contacts whenever it plays an A-side and whenever it tries to play a B-side. I'm not even sure I captured that action in the videos. I'd appreciate it if someone here could have a look and tell me if I've shot a video of the contacts.

Playing A-side

Trying To Play B-side, Turntable Reverses Rotation

Re: LPC 480 Won't Play B-sides

Posted: Wed Sep 25, 2013 9:36 am
by Rob-NYC
Bob, from the second video it is obvious what is happening here, the relay on the front of the mech should be in the "down" position at all times when the mech is scanning to the left or playing a B side. It is falling out (moving upwards) just before the stylus is set.

As I said before, this relay is electrically held st the start of a B-side cycle but mechanically held down by a linkage attached to the cam during play.

Try this: Using a stick or a gloved finger (full line voltage here) select a B and hold the relay down on the phenolic insulated part -not the blades, till the record starts to play. If it stays down by itself, the problem may be that a set of contacts on the cams is releasing too soon. If it pops up it is --likely-- the mechanical linkage.

A better shot of the B operation showing the relay and linkage might help here, but what is happening is pretty clear.

Rob/NYC

Re: LPC 480 Won't Play B-sides

Posted: Thu Sep 26, 2013 3:18 am
by Bob B
I haven't tried holding the relay down yet -- I think I understand where the "phenolic insulated part" is -- but before I do, I wanted to further illustrate with yet another video, that B-sides of 33-1/3 Little LPs will play upon being selected. Why would that be? Why would this happen only with the 45's? Once the little LP is done playing though, the record is not returned to the magazine, but the turntable reverses (as it does for 45s) and the record has to be rejected.

For the sake of brevity, I edited this video to show the selection of R6 (the B-side of a 33-1/3 Little LP), the first 15 seconds or so of it playing the record, and then jumping ahead to what happens after the record is done playing.

Does this in anyway change your opinion as to what the source of the problem is here? Why would it play the B-side of a 33, but not of a 45?

Plays B-side of 33-1/3 Little LP

Re: LPC 480 Won't Play B-sides

Posted: Thu Sep 26, 2013 4:07 am
by Ron Rich
Bob,
I know exactly what's happening--someone "messed with" the mechanical adjustment that holds the Reversing Relay. If you have the service manual, set it as it shows--if not. loosen the hold down nut and run the
Allen screw up, about a half turn--try it on both a 45, and 33. If that does not do it, run the screw up a bit more, and try again. Ron Rich

Re: LPC 480 Won't Play B-sides

Posted: Thu Dec 05, 2013 3:18 am
by Bob B
I'm happy to report that, more than 3 months after making my initial post here, my Seeburg LPC-480 was finally repaired today. Without a doubt, the greatest challenge was in finding someone to come out to the house. I spoke with no fewer than 3 techs who either (a) promised to call me back to set up an appointment and never did, (b) would only work on the phonograph if I brought it in to their shop, or (c) wouldn't work on it because it was too new of a model.

My 4th contact turned out to be a highly-skilled and very knowledgeable man who used to work as a service tech for the Wurlitzer distributor in Baltimore. He performed an adjustment on the reversing relay, cleaned up some contacts and gave it a proper lubrication. He liked the condition of the exterior but suggested the Tormat Control Center and the Auto Speed Unit be brought in for servicing/rebuilding. Apparently, a lot of what's in there are original parts, long overdue for replacement. He showed me how to remove both units so that I could bring them in to him, thus saving myself the expense of a service call. He's about 45 minutes away from me.

But for now, I am good to go and the box is loaded up with some terrific holiday music. It sounds great and works flawlessly. I'd like to take this opportunity to thank both Ron and Rob for their input in this thread. This is a great site, I always enjoy coming here and reading about other people's challenges.

Thanks again,
Bob

Re: LPC 480 Won't Play B-sides

Posted: Thu Dec 05, 2013 5:43 am
by Ron Rich
Bob,
Glad to have "helped"--a little, I hope--and thanks for the follow-up-
Ron Rich