Marantz Turntable Repair Question

[headponejack]

Hi all,
New to the forum and I have a question. I recently picked up a very nice condition Marantz from my local thrift store for only 20 bucks. Since I bought it, it's had some very obvious speed problems. I've repaired electronics as a hobby for close to a decade now, so I figured whatever was wrong was probably either dry lubricant or blown capacitors. I have since recapped both the PSU and motor board, cleaned and relubricated the motor, replaced the motor's AN620 chip, replaced the transistor on the power supply, sprayed contact cleaner and lubricant into the potentiometers, and replaced the power switch. All these repairs have, if anything, made the speed issue worse and made the output sound like noisy crap. I really don't want to abandon the repair since even after all I've sunk into it it's still a really good price for one of these, and taking it to a repair shop feels like admitting defeat. What else could I try? I suspect it's a problem with the motor since I know it's getting the correct power from the PSU. Any answers would be appreciated!

 

[SONDEKNZ]

Welcome aboard.

Providing the exact turntable model description will take you further here...

 

[headponejack]

Ha, I forgot this post didn't have it in the title. It's a 6150.

 

[headponejack]

bump, considering just dropping the 50 bucks it would cost to get a replacement motor at this point.

 

[sound hound]

All these repairs have, if anything, made the speed issue worse and made the output sound like noisy crap.

Welcome to Audiokarma! Hope we can help. It might help if you could provide more clarification of the problems you are having with it. What kind of speed issue? And what is the sound output problem? I think that the more information you can provide, the more likely someone could help you figure the problems out. Do you have a copy of the service manual? Not sure how many voltage test points it provides.