Technics SL15 Random Stops?

turning japanese
tommypenngotti
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Re: Technics SL15 Random Stops?

Post by tommypenngotti » 17 Jul 2018 02:27

belt replaced
Phono lube on gear
Lithium grease on rod

AsOriginallyRecorded
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Re: Technics SL15 Random Stops?

Post by AsOriginallyRecorded » 17 Jul 2018 05:10

As regards the push buttons on these units, they operate as one push on and one push off buttons. Extra pressure on the switch serves no purpose. A second light push will result in the alternate status (either on or off). The actual switch is an enclosed plunger type with internal contacts. The external switch faces actuate the "plunger" with a purely mechanical arm motion when the button is touched. Repeated pushing or sustained pushing will simply disrupt the on or off sequence. Push once...test function...push again, test function. One of the two positions will be on, one off, and the resultant operation may indicate the status of the switch position. Again, just trying to add clarity to the operation. Not to question the skill of your tech, but what type of lube has he been using on the sled? :)

tommypenngotti
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Re: Technics SL15 Random Stops?

Post by tommypenngotti » 17 Jul 2018 08:50

My Start & Stop buttons have a 2 position purpose...the first level push activates the arm movement , depress deeper push moves the arm faster ....are we on the same page ? I'll check on the lube and get back to you, thanks

AsOriginallyRecorded
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Re: Technics SL15 Random Stops?

Post by AsOriginallyRecorded » 17 Jul 2018 19:20

Yes, I believe the switches all function similarly. A single touch activates, holding the button "accelerates" the arm. My point is that they are momentary switches, so respond each time pressure is applied. The electronics programming responds in accordance with the number and duration of pushes. As to the lubricant, just trying to "poll" respondents to add to the database. I've had good results with a silicone based grease of an automotive origin, but am always interested in finding the perfect solution. As mentioned by Spinner45, lubriplate (white lithium) are very good for this purpose as well.Thanks for sharing! :)

ceservice
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Re: Technics SL15 Random Stops?

Post by ceservice » 26 Oct 2018 20:32

Hi guys...Just came across your posts regarding your issue as I have an SL-15 in for service that is experiencing the same. The tonearm drive belt needed replaced, but as I was bench testing, the unit would randomly stop, just like the stop button was pressed. Over the years, I have experienced many odd symptoms related to tactile switches. Random functions without the input of the user is mainly the problem(s). Replacing the tact switches would relieve these symptoms. However, this particular unit uses unusually large switches, with two functioning in series for each of the functions of play and stop. Having the feeling that such switches would be difficult to obtain, I drilled a small hole into the side of each switch, being careful not to insert the drill bit too deep into the switch as prevent damage to the internals. I then injected Deoxit into each switch and manually worked each switch. Currently in the test phase, I have not experienced a recurrence of the problem. If the problem returns, I will inform, but at this point, it appears that is a fix . If you choose to pursue , you must be VERY careful when drilling the hole into the switch, as you can easily damage them. You only want to drill enough to pierce the outer case and go no further!Use a variable speed drill or something that will turn very slowly.. I have used this technique on locking push button switches as well , with very good success .
If your symptoms get annoying enough, this might be something to try 8)

AsOriginallyRecorded
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Re: Technics SL15 Random Stops?

Post by AsOriginallyRecorded » 27 Oct 2018 02:38

Thanks for that insight and hint. I have a couple of such pieces of equipment, and once I get up the nerve, may investigate that procedure as a fix. Makes a lot of sense to me....I wish I had X-ray vision so I could actually see what these switches are like inside. Another "sticky note to self". Much appreciated ceservice! =D>

tommypenngotti
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Re: Technics SL15 Random Stops?

Post by tommypenngotti » 03 Jan 2019 09:31

ceservice : can you post a pic of the holes you drilled , it may be helpful to many users . Thanks

fscl
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Re: Technics SL15 Random Stops?

Post by fscl » 03 Jan 2019 14:48

ceservice wrote:
26 Oct 2018 20:32
Hi guys...Just came across your posts regarding your issue as I have an SL-15 in for service that is experiencing the same. The tonearm drive belt needed replaced, but as I was bench testing, the unit would randomly stop, just like the stop button was pressed. Over the years, I have experienced many odd symptoms related to tactile switches. Random functions without the input of the user is mainly the problem(s). Replacing the tact switches would relieve these symptoms. However, this particular unit uses unusually large switches, with two functioning in series for each of the functions of play and stop. Having the feeling that such switches would be difficult to obtain, I drilled a small hole into the side of each switch, being careful not to insert the drill bit too deep into the switch as prevent damage to the internals. I then injected Deoxit into each switch and manually worked each switch. Currently in the test phase, I have not experienced a recurrence of the problem. If the problem returns, I will inform, but at this point, it appears that is a fix . If you choose to pursue , you must be VERY careful when drilling the hole into the switch, as you can easily damage them. You only want to drill enough to pierce the outer case and go no further!Use a variable speed drill or something that will turn very slowly.. I have used this technique on locking push button switches as well , with very good success .
If your symptoms get annoying enough, this might be something to try 8)
=D> =D> =D> =D> csrvc

Great troubleshooting tip, will cross post to the "SL-7 Disassembly Problem" topic.

Thank you and welcome to VE....... :)

Fred

MikeMonaco
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Re: Technics SL15 Random Stops?

Post by MikeMonaco » 06 Jan 2019 06:46

Hello all,

I have the same exact problem described by others in this thread. I would like to try to fix, and would appreciate some pics of the drilled holes. Another idea that crossed my mind - has anyone attempted to just remove the stop switch from the circuit? if it's disconnected then perhaps this would rule it out (or in) if the problem doesn't reoccur.

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Re: Technics SL15 Random Stops?

Post by Spinner45 » 06 Jan 2019 07:59

MikeMonaco wrote:
06 Jan 2019 06:46
Hello all,

I have the same exact problem described by others in this thread. I would like to try to fix, and would appreciate some pics of the drilled holes. Another idea that crossed my mind - has anyone attempted to just remove the stop switch from the circuit? if it's disconnected then perhaps this would rule it out (or in) if the problem doesn't reoccur.
Over time, those tact switches, asides from natural corrosion issues, can become tired, causing "ghost" triggering.
The visible actuator button on the cabinet also becomes slightly weak, and not allowing the full release of the switch beneath it.
Cleaning was mentioned, and if for corrosion, may work, however it's better to replace the switch with a suitable replacement, and inspect the cabinet mounted actuator for issues.
Sometimes they can gently be "sprung outwards".

Going deeper, the circuitry and control board can be the source of trouble - slightly leaking or aged capacitors can trigger the IC into thinking the button was pressed - another form of "ghost tiggering".
Then extensive troubleshooting is required.

Remember, these things are showing their age now.

chgc
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Re: Technics SL15 Random Stops?

Post by chgc » 06 Jan 2019 13:14

Wild guess— problem caused, not by a power surge, but a power interruption. Faulty/dirty on/off switch? Bad power cord? Bad connection where cord plugs into back of turntable (perhaps owing to fatigue from repeatedly plugging/unplugging replacement power cord with wrong pin spacing)? Maybe try 12v power (being careful to use correct polarity, etc.), troubleshoot on/off switch.

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Re: Technics SL15 Random Stops?

Post by MikeMonaco » 11 Jan 2019 02:48

Thank you for your input and suggestions. I tried spraying electronic cleaner (Radioshack 6404345) from outside openings of the switches, but no help. I think I'll give it a go and open up the box for deeper inspection and cleaning. I've been hesitant to do this because it works flawlessly most of the time, and my fear is I'll just make it worse (or destroy it altogether). When it works, it's great, but when it abruptly stops right in the middle of a favorite song it can be unnerving.

I got a lot of good ideas on what and how to clean it from watching this video on youtube -- https://www.youtube.com/watch?v=jwP37kYzCUw.

I'll let you know how it goes.

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Re: Technics SL15 Random Stops?

Post by nolesw » 18 Aug 2019 23:14

Update to this post. I (hopefully had, not have) this issue with my SL10. Since fixing, it has played through 15 records with no issues. Origianlly, I would play a record, and usually about halfway through, it would stop, and return home. I took it apart myself many times, trying different things, making sure it was well lubed. That ended up being the biggest mistake. These turntables need very little lube, and the guide rod needs a dry lube. That is very critical, as someone has mentioned already. I had a light synthetic oil on mine, and that was too much, causing the issue for me. I personally would not trust your "Technics expert" or "Friend who has been working with electronics for years" unless they explicitly know this turntable. I believe a typical lubing for someone working on one of these for the first time would be grease on the gears, and oil on the guide rod, and you simply can not do that. Good luck!

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Re: Technics SL15 Random Stops?

Post by Rajkumar » 10 Oct 2019 05:07

I have Technics SL-10 and I am using more than 3 years everyday, tonearm guide already factory Teflon coated with my experience not require any lube, ensure guide free from dust or any old lubrication. If we clean very well guide tonearm can move smoothly on Teflon coating guide. Rajkumar