Anyone familiar with the Kenwood KD 750 turntable?

Send me a short mail, I'll supply you with pics and specs.
rgds
Al

An old friend of mine has a Kenwood KD750. The turntable speed becomes unstable when it has been playing for 30mins or so. Has anybody had a similar issue? Have you managed to repair this.?

Experienced slowdown speed, then NO speed from a KD750. No chance in hell repairing one without a service manual. The most complex circuit board I ever seen on a TT. NAND and NOR gates,Hex inverters,Flip-flops,OP Amp,several other ICs
uncrossable, and 4 transistors that are N.L.A.
Mine was a freebie and I'll buy the manual,but wouldn't bother looking at the inards unless you just want to be overwhelmed by complex circuitry. Good luck.

I have not looked at a 750, but many of the Kenwoods had a speed stability problem created by aging/oxidized/corroded switch components under the 33rpm/45rpm speed control buttons, which on many units was a toggle type switch.

If you play with putting subtle changes in pressure up and down on the speed change button(s), and observe crazy speed fluctuations, then a thorough cleaning of the switch internals may solve the problem.

I solved my speed problems by replacing the standard adjustment pots with 2 larger outboard ones mounted in the side of the bottom metal plate. The original pots were there only for setting the speeds to initiate the quartz lock when you press the 33/45 speed buttons. I can now spin up the speed to 78 rpm at the 45 speed switch setting. Mine was a little rough when I got it but I have tweaked it to satisfaction. Mounted with a Dynavector 50 it's a great sounding deck. I am interested in buying another 750 or 850 if someone has one with problems. Thanks