Technics sl-1401 problem

[Roel Welters]

I lubricated it and let it run for 8 hours without an error, then i powered it off for about 4 hours and powered it back on. Now it has the error again, so i guess it's not mechanical since the platter runs free. The error can be triggered by applying some drag to the platter. What would you fix before recap?

 

[Roel Welters]

The position of the counterweight looks a bit awkward to me, it actually is not in a straight line with the arm, is this normal with this model?

 

[Roel Welters]

Link to the service manual: https://www.vinylengine.com/library/technics/sl-1401.shtml

 

[JP]

What would you fix before recap?

It could very well be some bad caps causing the issue that need replaced. I'm a firm believer in finding and fixing the problems before summarily replacing parts, though in this case a recap is likely to fix the problem.

If you want to troubleshoot, measure the voltage and ripple of the supplies, Vcc at all the ICs, particularly 201 and 202. If that all checks out, then check the PLL alignment - adjustment procedure C in the service manual.

After you get it running stable do a full recap and re-calibrate.

 

[Roel Welters]

The counterweight shaft is a bit loose, were do I thighten that?

 

[Roel Welters]

I just finished recapping the whole board as I did not fancy troubleshooting. Well it's a partial succes:
- If i press start directly after power at 33 rpm it skips forwards/backwards +-10 times and then it runs smooth
- At 45 rpm it' s spot on.

If I power it up for 10 seconds before pressing the start button, everything is ok.

I would like to troubleshoot it, but since the problem disappears after 10 seconds that will not be easy.

So, what could make the 33rpm speed unstable for 10 seconds after powering up?

 

[Alobar]

I still would suspect one or both of those speed buttons are sticking, but I am not an expert. I have the same model and it is the case with it.

 

[Roel Welters]

Fixed it!
There is a Tracking pot, on the front side, just under the cover, here you can adjust the speed.

 

[Roel Welters]

Here's the picture.

 

[migyver]

reviving an old thread here, I know...

Just picked up one of these for $100CAD, it was dirty as all get out, but it cleaned up real nice and sounds fantastic, will likely become my daily driver.

Does anyone know if the start/stop button can be removed without full disassembly? I was hoping it could pop off so I could get in there to clean the grime out. The button works but it barely moves and I'm not sure if that's normal? There's usually tons of videos on YouTube or on here that would contain all of this info, this seems to be a pretty rare model. I don't have any Deoxit not sure if there's anything similar available hopefully locally?

 

[Roel Welters]

Hi Migyver, congratulations on your purchase, a bargain!
May I suggest you download the service manual from https://www.vinylengine.com/library/technics/sl-1401.shtml
You will have the explosion drawings, my suggestion is that you strip the unit so you can remove old grease and grime and give all non-electrical stuff a nice sponge bath.
The buttons can be removed from the top but it is much safer, in terms of damaging them, to do it while disassembling the unit.
They operate tiny micro switches that may require treatment with contact cleaner, or even replacement. You will find these in any electronic store.
It is pretty straightforward as long as you work organised and take pictures of every step you take. Good luck!

 

[migyver]

Thanks for the advice. I must say that the more I use it the better it seems to get. The buttons are now all working perfectly, this unit was stored and powered on approximately 3 times in the last 35 years. I did take some of it apart when I got it to clean some of the dust (surprisingly not a lot, given the age of the unit). I did all a bit of lube to the spindle, but it would be a good idea to get right on there and remove the old gear.

Going to try a Nagaoka MP-110 on this. Seems to be a well reviewed cart for deck. It's coming in from Japan so it might be a few before I get to try it.

 

[migyver]

I've taken most of it apart and am impressed at how clean everything was. The DD bearing had no sign of gunk or solid grease. I regreased it and put it all back togehter, the only thing that had some caked up grease was around the auto-return gear and spring. The motherboard did not have any noticeable dirt caked on. A bit of isop alcohol and a cotton swab and it's clean as the day it left the factory. The buttons are all articulating properly now.

All that's left to do is wait for my new cartridge and vinyl wrap. I have a plan hide the crack next to the dustcover hinge that I fixed with CrazyGlue, since it's still quite noticeable. I'm planning on wrapping the inside of the back panel of the dust cover with black mat wrap, and maybe throwing on a Technics sticker for good measure. We'll see what it looks like, worst case I'll order a replacement.