Sony SL-300 Betamax VCR eject problems - Videokarma.org TV - Video

Captainclock · #1 12-21-2015, 08:15 AM

Hello everyone I'm currently working on a mid-1980s Sony SL-300 SuperBeta Betamax VCR that is having issues with not wanting to eject the tape, it plays, rewinds, fast-forwards, and pauses just fine but when you go to try and eject the tape the eject mechanism will load the tape back into the cassette housing and attempt to unload the tape from the VCR but then instead of ejecting the tape out of the VCR it makes a loud clicking noise like the mechanism is jammed or something (its a direct drive loading/eject mechanism with a worm gear that is driven by a small 12 volt Marbuchi motor) and then the tape goes back into the VCR where the mechanism loads the tape back around the heads again.
By the way this my first time ever working on a Betamax machine as I have never seen one in person before until now let alone service one, only thing I know about Betamax is that my parents wedding was filmed on beta, and that's it.

Any ideas as to what could be causing the issues with this Betamax's loading/eject mechanism?

Any help would be appreciated.

-Levi

ChrisW6ATV · #2 12-21-2015, 07:05 PM

Others may have better ideas, but I would watch the unloading attempt and reload that happens, and see if that same motor does both actions by reversing direction, and also look to see if it or another specific motor and/or belt setup does the actual cassette raising and lowering or not. If the one motor seems that it should do everything, you could try hitting Eject, and pulling the power plug right when the tape unload is complete, then try manually spinning the motor further in that direction while carefully analyzing/encouraging the cassette raising action. It could be a lubrication problem or something that got jammed.

Captainclock · #3 12-21-2015, 09:35 PM

Quote:

Originally Posted by ChrisW6ATV

Others may have better ideas, but I would watch the unloading attempt and reload that happens, and see if that same motor does both actions by reversing direction, and also look to see if it or another specific motor and/or belt setup does the actual cassette raising and lowering or not. If the one motor seems that it should do everything, you could try hitting Eject, and pulling the power plug right when the tape unload is complete, then try manually spinning the motor further in that direction while carefully analyzing/encouraging the cassette raising action. It could be a lubrication problem or something that got jammed.

I have actually tried something similar to that where I tried to raise the mechanism by hand while the motor was running and I would get the tape out but then the mechanism would just go back into the VCR. There's only one motor running the entire loading mechanism from what I could see (besides the motors that are involved in kicking the tape out of the heads and back into the cassette case) and it does reverse itself when you hit the eject button compared to when it loads the tape (which it has no problems loading the tape) but when it comes to ejecting the tape it gets it halfway out of the VCR and the motor for driving the loading/eject mechanism just immediately grinds to a halt and when I try to nudge it along it doesn't help much unless I force it (which I know forcing it won't help it any and will probably make things worse) but it acts like the motor might have a dead spot in it.

Electronic M · #4 12-21-2015, 09:28 PM

I had a Sony beta where there was a guide tab broke off on the cassette holder part of the load mechanism that rode in a track (there was one on each side) and that tab being busted off prevented the mech form ejecting.

Captainclock · #5 12-21-2015, 09:36 PM

Quote:

Originally Posted by Electronic M

I had a Sony beta where there was a guide tab broke off on the cassette holder part of the load mechanism that rode in a track (there was one on each side) and that tab being busted off prevented the mech form ejecting.

Where would that guide tab be? So I could see if maybe that's what happened with this one.

Electronic M · #6 12-21-2015, 10:34 PM

Quote:

Originally Posted by Captainclock

Where would that guide tab be? So I could see if maybe that's what happened with this one.

Assuming yours is a front-loader....There is a a tray the cassette rides in between the play position and ejected position. There will be plastic/metal guides/tracks on both sides of that tray. The tracks should have an L shaped slot in them that the tab/pin of the tray rides in as a guide....There is at least one on each side of the tray in most VCRs.

Captainclock · #7 12-21-2015, 11:24 PM

Quote:

Originally Posted by Electronic M

Assuming yours is a front-loader....There is a a tray the cassette rides in between the play position and ejected position. There will be plastic/metal guides/tracks on both sides of that tray. The tracks should have an L shaped slot in them that the tab/pin of the tray rides in as a guide....There is at least one on each side of the tray in most VCRs.

Yes, its a front loader model, and, from what I could see of the unit when I had it open it didn't seem like there was anything broken off although when I took the mechanism apart to check the gears out it looked like something small and black fell out that wasn't part of the gear drive mechanism, was that maybe the tab you were talking about? I didn't see where the tab landed as it fell out before I could see where it landed at.

Electronic M · #8 12-22-2015, 12:30 AM

Quote:

Originally Posted by Captainclock

Yes, its a front loader model, and, from what I could see of the unit when I had it open it didn't seem like there was anything broken off although when I took the mechanism apart to check the gears out it looked like something small and black fell out that wasn't part of the gear drive mechanism, was that maybe the tab you were talking about? I didn't see where the tab landed as it fell out before I could see where it landed at.

That small black thing may have been it. My deck was a odd Sony superBETA unit (odd because it did not have HiFi). It had a cap problem with the capstan motor that would stop the capstan at random (needed to be hand spun occasionally to fix it/keep it from interrupting playback) and I ran it on it's side to baby sit that until I fixed it. A couple times it fell over to normal operating position with a tape in it and the weight of the tape in the fall broke that tab, and later the superglue bond I used to fix it.

If you eventually decide you can't fix yours and want to part it out/get rid of it, post some pictures of the capstan motor....If it is the right one I'd be interested in buying it off you.....When I changed the cap my soldering iron melted a bit of the plastic tire on the capstan rotor.....That tire is essentially a loop of magnetic tape that is read by a tape head to make a speed feedback signal...It don't play quite right with a melt spot.

ChrisW6ATV · #9 12-22-2015, 03:22 PM

If "you took the mechanism apart and a piece fell out", then you definitely need to figure out exactly what it is and where it belongs before anything else is done. Of course, it could have even been a piece of a toy that a child put inside once, but you need to find out for sure. There is no point in even thinking about any other repair action until that is known and fixed, first.

This kind of "oops" event has happened to most of us, and the only solution is to learn from it, typically by being even more attentive, even when we though we were paying high attention to detail already.

Captainclock · #10 12-22-2015, 11:50 PM

Quote:

Originally Posted by ChrisW6ATV

If "you took the mechanism apart and a piece fell out", then you definitely need to figure out exactly what it is and where it belongs before anything else is done. Of course, it could have even been a piece of a toy that a child put inside once, but you need to find out for sure. There is no point in even thinking about any other repair action until that is known and fixed, first.

This kind of "oops" event has happened to most of us, and the only solution is to learn from it, typically by being even more attentive, even when we though we were paying high attention to detail already.

I was trying to be careful, I was taking the mechanism apart thinking that there wasn't anything broken or loose in the mechanism and then the part whatever it was fell out and I only saw it from the corner of my eye so I couldn't even see where it fell to and it looked like a really small part so even if I were to try and locate that part I doubt I'd be able to find it because I don't even know where to start looking for that part because like I said I didn't even see where it fell.

ChrisW6ATV · #11 12-23-2015, 01:19 AM

Well, plan B might be to just look over the whole mechanism to see if a piece might have broken off somewhere. I remember having a part of the mechanism in my first VCR break off, and I rigged something in place to fix it. That was in 1980, on a one-hour Beta machine.

Captainclock · #12 12-23-2015, 09:18 AM

Quote:

Originally Posted by ChrisW6ATV

Well, plan B might be to just look over the whole mechanism to see if a piece might have broken off somewhere. I remember having a part of the mechanism in my first VCR break off, and I rigged something in place to fix it. That was in 1980, on a one-hour Beta machine.

Well I could do that but of course it would be even more helpful to know where the part may have come from to begin with. If it was one of the tabs that Electronic M was mentioning then I might know where to look, but if it wasn't then I'm not sure where else to look otherwise.

Electronic M · #13 12-23-2015, 01:13 PM

Try (with the unit unplugged) turning the motor shaft/worm gear by hand (try to manually move the tray through it's full load/unload cycle) and see how much resistance there is....It is possible the grease on the load gears is starting to act more like glue....It's been about 5 years since I worked on mine, but IIRC the cassette load mech needed needed some fresh grease.

Load motors usually are not a high failure item in Sonys (you could try removing it letting it free run, and maybe applying mech resistance with your fingers to check it). Only load motor I've ever had to change was in a NEC S-VHS deck.

Captainclock · #14 12-23-2015, 01:30 PM

Quote:

Originally Posted by Electronic M

Try (with the unit unplugged) turning the motor shaft/worm gear by hand (try to manually move the tray through it's full load/unload cycle) and see how much resistance there is....It is possible the grease on the load gears is starting to act more like glue....It's been about 5 years since I worked on mine, but IIRC the cassette load mech needed needed some fresh grease.

Load motors usually are not a high failure item in Sonys (you could try removing it letting it free run, and maybe applying mech resistance with your fingers to check it). Only load motor I've ever had to change was in a NEC S-VHS deck.

Well maybe, but that's what its acting like though, and maybe it is just a matter of just needing a relube, but I'm not sure what you would use to relube this with, the original lubricant is a bluish color, would maybe using some silicone based lubricant (like what they use on bicycle kickstands) or some lithium grease work to lubricate this VCR's loading mechanism?

Also is the Inside of the VCR I'm working on the same as the inside of yours?

Electronic M · #15 12-23-2015, 01:42 PM

Quote:

Originally Posted by Captainclock

Well maybe, but that's what its acting like though, and maybe it is just a matter of just needing a relube, but I'm not sure what you would use to relube this with, the original lubricant is a bluish color, would maybe using some silicone based lubricant (like what they use on bicycle kickstands) or some lithium grease work to lubricate this VCR's loading mechanism?

Also is the Inside of the VCR I'm working on the same as the inside of yours?

White Lithium grease is what I use on VCRs...It works well.

It's been 5 years since I last opened mine, so the memories are foggy. It's under a pile of stuff on a shelf presently so it might be a couple of days before I can get it open again...