Need help with SL 1700MK2

[ccrnnr9]

I removed the retaining c-clip and washer, and was able to pull the gear away just enough to see that, behind the gear, the bushing that the outside nut was threaded on had opposite flat sides. Gripping these flat sides on the bushing with a small needle nose pliers, I was able to tighten the outside nut (9mm socket). It was very tight at first (appeared dried out grease flaked out of the threads once I got it turning). I tightened the nut maybe a turn, or a bit more. Note that if you don't get behind this gear and securely hold this threaded bushing, it will simply turn without any effect. It would have been much easier to work on if I could have removed the gear assembly, but unfortunately, the way it is attached in its location, it appears difficult to remove so I tightened the clutch in place.

Resurrecting and old thread but hoping this works for me as well. I've replaced ICs and once I can find current adequate replacements will order replacement transistors. The cueing and stop mech now work after replacing 4xx series ICs but the auto return alas is still not working.

 

[Aerobat]

Another zombie thread comes to life. I don't even remember replacing transistors in my old 1700MK2, but I guess I did!

 

[ccrnnr9]

As I'm having trouble finding any of the part numbers listed a few pages back regarding transistors specifically, I compiled a list here of *hopefully* compatible and available (from Mouser) part numbers. I've just looked at specs of the original Panasonic parts and tried to search for transistors with identical or very close specs. Would be nice if someone more in the know than me would check my work:

for Q501-504, 508, 509, 512 > 2sd636 -- use BC548 or BC548BBK
for Q505 > 2SB641 -- use BC307B
for Q506 & 510 > 2SD638 -- here are some that could work but specs don't match well - curious if anyone has thoughts?
for Q507 & 511 > 2sb643 -- maybe some of these?

 

[Thunderbox]

I recently acquired a Technics SL-1700MK2, it had the usual problems (sticky power button, and no cue/auto return), cleaned switch and replaced belt, however, the cue and auto return still doesn't work, i am pretty sure the problem lies in one of the IC chips, but...I can't find any replacements, so my question to you expert folk, is, is there any compatible IC that i can use as a replacement or is this unit FUBAR?
The platter spins, it holds speed, tone arm is good, it's missing the feet, but i am not worried about that,as i plan on doing my own.

Any help is appreciated, as always.

John.

I just repaired a 1700 MKII today. Exactly the same symptoms as yours. Put a small screwdriver under the tone arm lift and put a little tension on it, in an upwards direction. If the ram is seized it will not move. If it doesn't move it needs to come apart. Once I got it apart I used some brakeklean on it and it freed right up and everything works. The mechanism is mechanical but the mechanism won't let the return operate unless the arm is in the lifted position. Otherwise a lot of people would be replacing the styklus also.