Vintage Technics SL-1300 poltergeist--help!

To clarify, when this doesn't happen one couldn't ask for a better playback experience.  It can't be forced to misbehave and doesn't seem to matter whether playback was initiated with "Start" control or via user manually starting playback. Also independent of brand-new albums or old favorites.

I don't like automatic tables. If it was me I'd remove the automatic parts and just run it as a manual. 

Take a look @ the following thread (think you have a MkI, but not certain).

DeKay

I see nothing in that discussion relevant to this problem.  I realized about 1/3 into it that I'd read it before but continued through again.

Yes, this post is specific to the original SL-1300 which, of course, Technics did not refer to as "Mk I"

I think it's the Firesign album....

But, seriously....the arm return cam assemblies on auto tables can be real Rube Goldberg affairs; what looks 'fine' can have wear or 'sticky' issues.  Yours looks like the diameter cam, it's spring, or some combi is losing its' mind...

....has service manuals that you can sign in and download por gratis.  Since your 1.3K is definitely off warranty, don't be afraid to go take a look for yourself.

Clean/oil/grease is relatively easy, but Ham Hans needs to be delicate in his endeavours.  Most shops don't like to mess with vintage, since there's no $s' there.  Lots of time, parts may be n/a unless one finds a donor...

Creates a bill that can rival or exceed the worth of the TT, so how attached are you to the unit becomes the question.

Time vs. trials, yet again...Good luck. *s*

This video shows the "underside" mechanisms.

DeKay

Thanks!  He really never addresses weird channel (or whatever on that plastic gear/cog wheel/whatever...).  I need to go back further than where it started playing for me.  I'd like to see what interacts with that channel, if anything.  There must be something--else why have it molded in like that?  In other words, when he is ready to button it up there appears to be nothing that is going to touch it except on the side that becomes hidden during reassembly.

I can't understand why that "channel" exists when I see nothing that interacts with it.  At first, I thought it's there simply to provide better strength or rigidity but that wouldn't dictate the shape of that...???

Mine began acting up and repair attempts weren’t successful. Being someone who doesn’t love the automatic turntables, I gutted the automatic parts, set it up as a manual, and it’s phenomenal—basically an SL-1200 in functionality. New Ortofon cartridge was a big help too. Sound and function are flawless now for four years.

Is the onset of the malfunction temporally related to when you removed the counterweight?

And yes, I think the channel could be there to enhance structural rigidity.

I forgot to return here (OP is me).  In my strange case and video, 3 people minimum did not notice that the Ortofon headshell had a lift arm that protruded higher than the standard Technics headshell.  In fact--that was the problem, full stop.  I discovered the headshell's arm was dragging on the surface of the dust cover until it progressed far enough the dust cover and headshell no longer had interference with one another.  No problem with the SL-1300 works at all.

I am a moron.

Serves you right for using the dust cover while playing records.

That was a joke, by the way. I don’t use a DC during play because the ones I’ve used add an unpleasant coloration and/or feedback related sonic problems. Others take a different (minority) view.

I am a moron.

I've done worse.