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Technics SL-QD33 Automatic not working

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Technics SL-QD33 Automatic not working

Postby texasforever6 » 17 Jan 2013 21:45

I received a Technics SL-QD33 Quartz Direct Drive Automatic Turntable System. It's my first turntable. The problem is the automatic arm doesn't work, and thus, the repeat doesn't work either. Otherwise, it works fine manually. I really want the automatic and repeat feature to work :(

I got it off craigslist. It's in good condition and it worked fine when it was shown to me. I'm afraid maybe the car ride was a little bumpy and threw something off?

I have a record on, I press the start button and light is on, makes noises, goes up, clicks, makes noises and goes back down. It doesn't move side to side automatically otherwise.

If anyone knows what the deal is, I'd really appreciate it.
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Re: Technics SL-QD33 Automatic not working

Postby plyscds » 18 Jan 2013 18:04

I have had a similar problem with an SL-D303 which I bought used. Though I have never looked beneath the platter of a QD33, I noticed your platter mat has cutouts for record size detection fingers, and it appears similar to my D303 platter.

The fully automatic entry level Technics turntables will act as you described if they think no record rests on the platter mat. You have to have your platter mat positioned so that the size detection fingers can poke up through the mat, and there are rectangular holes in the mat to make this obvious (just covering the basics).

On my D303 there are two size detection fingers. A 7-inch record will depress only the inner finger, and a 12-inch record will depress both inner and outer fingers. The depression of a finger by the presence of a record causes that finger to lower a shorter arm below the platter.

On my D303, when play starts, an arm from the tonearm assembly protrudes into the area under the platter. This arm has two detentes, or rest positions, it can be pushed into. If the inner 7-inch finger only is depressed, the protruding arm is pushed into it's first detente and the tonearm lowers the stylus for a 7-inch record. If both size detection fingers are depressed, within 2 platter revolutions the protruding arm will have been pushed to it's second detente, and the tonearm will lower the stylus for a 12-inch record.

On my D303 I discovered that removing the size detection finger assembly completely from the platter will let the turntable behave like a semi-automatic, raising the tonearm at the end of play with manual stylus placement at the beginning of play. However that may be risky as no replacement assemblies are available as new units (or so I am told by an official Technics repairman). What actually revived the automatic functions on my D303 was disconnecting the small thin wire springs from the size detection fingers and bending them so they exerted a good bit more force on the fingers. They are very thin metal, and I assumed they had weakened over time. I am guessing, with my turntable, that if those springs aren't strong enough the fingers below the platter aren't able to push the protruding arm to any detentes, so if the protruding arm stays all the way out the turntable assumes no record is on the platter and shuts itself down. This is hard to verify because I can't see under the platter to verify what really happens. It is simply a best guess based on some measurements and knowing what has to happen with the protruding arm to make correct placement happen. I was able to explore some under platter functions by unplugging the turntable, removing the platter, and turning the motor shaft by hand. (You shouldn't run these direct drive motors without the platters in place! The magnets in the center of the platter underside are a vital part of the motor.) And, this "fix" may or may not apply to your situation.
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