Technics SL-1700 Mk2 start problem

[Impunity]

I have a start up problem with my 1700 Mk 2. The cue motor works both up and down, but the platter doesn't revolve when moved to the record. I expect there's a switch, either cam operated or photo-electric but before I pull this apart, I wondered if anyone else has had this problem.
Regards John L.

[Galu]

Have you checked the service manual for information?

TECHNICS SL-1700MK2 SERVICE MANUAL Pdf Download.

[Impunity]

Originally Posted by Galu

Have you checked the service manual for information?

TECHNICS SL-1700MK2 SERVICE MANUAL Pdf Download.

Yes I have but it doesn’t cover this particular issue. It does cover cueing and the issues related to that.
I can likely trace it but if I can start with some wisdom from others it might save some time.
Regards John L

[Galu]

This thread on an SL-1700 talks about a microswitch and the plastic lever which operates it.

The solution was to the clean the gummed up lever and re-lubricate it.

Dismantling instructions and photos are included. May apply equally to the Mk2?

Technics SL1700 platter won't spin | Audiokarma Home Audio Stereo Discussion Forums

[Impunity]

Originally Posted by Galu

This thread on an SL-1700 talks about a microswitch and the plastic lever which operates it.

The solution was to the clean the gummed up lever and re-lubricate it.

Dismantling instructions and photos are included. May apply equally to the Mk2?

Technics SL1700 platter won't spin | Audiokarma Home Audio Stereo Discussion Forums

Thank you. I first tested the IR switch under the tone arm which was OK and then the two NPN transistors associated with the drive board and they were fine. Then! I had printed out a clear copy of the circuit diagram and pin readout numbers on the AN6680 IC which turned out to be faulty. I suspect the two AC supply wires that had been badly wire wrapped may have been the cause of failure as one of the wires only had one strand still intact. So I'm sourcing a new IC and hopefully that will fix the problem. Even though these TT's are overly complex, I hate to see them end up in the dump or re-cycle. With luck this will give someone enjoyment for years to come.

[Galu]

Glad you are moving towards a solution to the problem.

Hope you can report back with news of your success.

Yes, the SL-1700 Mk2 is a good example of Technics' engineering.

I've owned a Technics SL-QX200 from new (1983) and it has never gone wrong.

It's a solidly engineered turntable, but often overlooked because of its P-mount (T4P) cartridge system.

[Mark Tillotson]

Originally Posted by Galu

This thread on an SL-1700 talks about a microswitch and the plastic lever which operates it.

The solution was to the clean the gummed up lever and re-lubricate it.

This is a common issue with many parts of many turntables - the grease used picks up dirt and dust over the years and dries out / hardens. Careful cleaning and relubrication with sparing amount of silicone grease is worth doing to any part that might need it. In theory a dry lubricant film would fare better, but preventative maintenance every decade isn't too onerous and its best not to try a different solvent in case any of the plastic parts disolve/soften. White silicone grease is very commonly used in record / tape decks, DVD drives, etc and it pretty stable all things considered, and most importantly doesn't attack rubber.