Technics SL-QD22 repair?

[zaibatsu]

Edit - It's actually SL-QD33 sorry!
I'll preface this by saying I have zero experience with turntables.

However my father dropped this off for me to repair, and I'm wondering if anyone could help me troubleshoot it, and/or maybe suggest if it's worth fixing or not. I do recall it sounding nice and clear back when it was working and I have no doubt he'd prefer to see it repaired than have a replacement.

When I turn it on the lights turn on and all the buttons work, but the table doesn't spin, and the arm doesn't move. Does it need a disc on it for those to happen?

Appreciate any suggestions

 

[zaibatsu]

I've played around with it and it seems both motors work fine, at one point I got the turntable to spin (speed selector works), and if I wind the tonearm motor one way it'll reset itself on power up.

However, the tonearm motor doesn't seem to actually move the arm (and the arm feels easy to move around, like it's not attached to anything - I'm not sure if that's normal or not) so I wonder if some of the mechanism is broken, and perhaps the inability to move / sense tonearm position is why it won't often turn on the turntable motor itself.

I also noticed the "large" side of the disc size detector never pops up, does that mean it's broken?
The "small" side pops up again if you push it down, but the large side just stays down and nothing lifts it.

 

[tmsears]

You might want to take a look at the service manual, you can get it from here: https://www.vinylengine.com/library/technics/sl-qd33.shtml
The large disc detector may have the spring is loose or broke on it. These types of size detection systems usually have an IR emitter or photo-detector of some sort and the little "switches" on the platter are usually just spring loaded shutters that close and open when a record rests on top of them.

I don't know a lot about this particular turntable but maybe it is a start.

EDIT: it looks like this unit has a mechanical index system for size detection. The detectors are little spring loaded "fingers" that strike an index cam connected to the arm assembly it looks like, but don't quote me on it.

 

[boreas]

Edit - It's actually SL-QD33 sorry!
I'll preface this by saying I have zero experience with turntables.

However my father dropped this off for me to repair, and I'm wondering if anyone could help me troubleshoot it, and/or maybe suggest if it's worth fixing or not. I do recall it sounding nice and clear back when it was working and I have no doubt he'd prefer to see it repaired than have a replacement.

When I turn it on the lights turn on and all the buttons work, but the table doesn't spin, and the arm doesn't move. Does it need a disc on it for those to happen?

Appreciate any suggestions

Yes, but your father would presumably known that, since he apparently used it for some time.

When you say that the arm doesn't move do you mean that it doesn't respond to START being pressed or do you mean it's immovable?

John

 

[zaibatsu]

I meant to update this thread but I ended up getting the whole thing working for the most part.
The motors wouldn't actually work most of the time, I only got the turntable to spin once and couldn't again - I suppose it was just enough to know that the motors still worked and something else was wrong.

The problem ended up being the 47uF capacitors littered throughout the thing, they were all made by TK (Toshin Kogyo - an el-cheapo Japanese brand) and all down to 9 or 10uF. I think this was a bad batch, explaining the common problems on the net where people find it works for a while after turning the motors by hand. All the other caps measured fine (I replaced them just to be safe since I don't want to fix it twice) so I think the 47s in particular must have been bad globally.

So now the turntable spins, the arm operates, the cueing works, and when you press stop the arm returns to its correction position and drops down into the holder.
It plays music fine and the speed settings work too.

The one thing that doesn't work is the initial positioning of the arm, it goes right to the end of the record instead of the start so you have to manually position it at the start. I figured it's not actually the size detection trigger to blame because the "non working" large disc flap is always in the down position and if there's a record on the table that flap can't pop up again - the only "broken" thing is the return mechanism (not spring loaded btw, just weighted slightly so that gravity returns them, bad one must have a little weight missing). So basically as it currently is, it should always think there's a large disc on there (which would be fine) but it doesn't - so I think there's a problem with the actual mechanism that those "fingers" are supposed to trigger.

I think the mechanism is not being triggered, so it'll be a bigger problem than thefingers themselves.
I'll update the thread if/when I figure it out, but it can wait for now.

@tmsears I made all the adjustments in the manual about a week ago (that all went well), but even with the manual and table in front of me I found it a bit tricky to correlate the actual size detection mechanism to their pictures, let alone figuring out what was broken. No rush but I'll have a look sometime in the future and maybe post up some pics if I can't figure it out. Cheers!

 

[jeffpaletz]

I haven't worked on this model before but the problem of the tone arm going to the center of the record instead of landing at the right spot on other models I've worked on has been caused by dried out lubricant. There is a part that has to move to the proper location that stops the arm at the right spot, either for 7" 10" or 12" records. Make sure the various parts of the mechanism inside are not stiff and hard to move. Re-lube the mechanism and that should fix the problem.

 

[tmsears]

@tmsears I made all the adjustments in the manual about a week ago (that all went well), but even with the manual and table in front of me I found it a bit tricky to correlate the actual size detection mechanism to their pictures, let alone figuring out what was broken. No rush but I'll have a look sometime in the future and maybe post up some pics if I can't figure it out. Cheers!

Yeah, I skimmed the manual and it is about as clear as mud on how to calibrate the thing. Did you make only electronic adjustments or did you do the mechanical adjustment near the arm as well?

 

[zaibatsu]

Yeah, I skimmed the manual and it is about as clear as mud on how to calibrate the thing. Did you make only electronic adjustments or did you do the mechanical adjustment near the arm as well?

Yeah after doing all the electronic adjustments I did the mechanical adjustment near the arm as well, from memory there was two of them.

One of them was the starting position adjustment, I guessed before trying it that it wouldn't affect my problem (since it sounded like a fine adjustment and on mine the arm is nowhere near where it should be) and sure enough it didn't do squat.

It took me a while to realise too but there are two adjustments made through that same hole, turns out when you move the arm (to above the record, or to the rest position), it positions a completely different adjuster screw under that hole! Might help someone else in the future, the manual didn't mention that.

I think the problem will be something broken or clicked out of place that should be triggered by those disc size detection fingers, I've found it pretty tricky to understand how that works though, and I think I'll have to pull apart the tonearm positioning mechanism after I figure out what I'm looking at compared to the pictures in the manual. I also wonder if I popped something out of place or damaged something while fiddling around initially trying to get it to work.

It's definitely more complicated than I thought, I think being fully automatic this table has a bit more going on than simpler ones, even though it's not high-end or anything.

Make sure the various parts of the mechanism inside are not stiff and hard to move. Re-lube the mechanism and that should fix the problem.

Thanks but I don't think that's the problem in this case, everything seems to move fine and the two types of grease that were on parts (transparent grease on gears and white ceramic grease on bushing/shaft interfaces) were both fluid/smooth and not sticky or gummed up at all. I'll pull apart the mechanism more thoroughly soon though and see.

 

[JimBanville]

I meant to update this thread but I ended up getting the whole thing working for the most part.
The motors wouldn't actually work most of the time, I only got the turntable to spin once and couldn't again - I suppose it was just enough to know that the motors still worked and something else was wrong.

The problem ended up being the 47uF capacitors littered throughout the thing, they were all made by TK (Toshin Kogyo - an el-cheapo Japanese brand) and all down to 9 or 10uF. I think this was a bad batch, explaining the common problems on the net where people find it works for a while after turning the motors by hand. All the other caps measured fine (I replaced them just to be safe since I don't want to fix it twice) so I think the 47s in particular must have been bad globally.

So now the turntable spins, the arm operates, the cueing works, and when you press stop the arm returns to its correction position and drops down into the holder.
It plays music fine and the speed settings work too.

The one thing that doesn't work is the initial positioning of the arm, it goes right to the end of the record instead of the start so you have to manually position it at the start. I figured it's not actually the size detection trigger to blame because the "non working" large disc flap is always in the down position and if there's a record on the table that flap can't pop up again - the only "broken" thing is the return mechanism (not spring loaded btw, just weighted slightly so that gravity returns them, bad one must have a little weight missing). So basically as it currently is, it should always think there's a large disc on there (which would be fine) but it doesn't - so I think there's a problem with the actual mechanism that those "fingers" are supposed to trigger.

I think the mechanism is not being triggered, so it'll be a bigger problem than thefingers themselves.
I'll update the thread if/when I figure it out, but it can wait for now.

@tmsears I made all the adjustments in the manual about a week ago (that all went well), but even with the manual and table in front of me I found it a bit tricky to correlate the actual size detection mechanism to their pictures, let alone figuring out what was broken. No rush but I'll have a look sometime in the future and maybe post up some pics if I can't figure it out. Cheers!

Could You please tell me how your tested the bad caps? I have the similar SL-QD33 with the same issues. THANKS!

 

[zaibatsu]

Could You please tell me how your tested the bad caps? I have the similar SL-QD33 with the same issues. THANKS!

I'd highly recommend replacing the whole lot, the TK (Toshin Kogyo) branded caps in particular are absolute rubbish, clearly this was a cost-cutting exercise because the rest of the Technics gear in that period/lineup (eg. amplifier) uses better quality parts. Make sure you take note of any bipolar items and replace like-for-like too.

I used a radial capacitor and bent out the legs flat to replace the large 2200uF one, works great (and they are priced a bit more reasonably than axial caps).

You can get the Mega328 component tester for around $10 off the 'bay, which works a treat and will be handy for similar work in the future - but in this case I'd replace them all as it's not a hard job anyway - especially if you plan to use the table for a while. Keep in mind you need to desolder the caps to test them, which is why it's easy enough to replace at that point.

It should sort out your issues. Mine has a mechanical problem with detecting the record size which I haven't got around to finding/fixing yet, but everything else works nice now.
Good luck!