hifi engine

Sony TC-277 slows down

nexar's picture

I have a Sony TC277 that slows down after about an hour playing time.
I have read on other forums that it was the idler wheel wore out, but I don't think that is the case.
I have cleaned and lubed the recorder, and cleaned all rubber wheels and belts.
The tension is not too tight,,the tape flows freely through the heads at the right speed for about 45 minutes, then it slows down.
I can turn the recorder off until it cools down, and it plays the normal speed.

Has anyone had this problem with A sony tape deck? Any help would be appreciated.



Sony TC-277 slows down

I haven't worked on a sony reel to reel for a while, but this sounds like a dry bearing somewhere. I would check the flywheel bearing to see if is totally free. a small turn of the flywheel should allow it to spin a revolution or two. If it stops right away, you will need to clean out the bearing and relube
Also check the pinch roller bearing to make sure it isn't binding.
The Rew pully, and rewind reel table, and the tape counter can bind as well, causing drag on the motor.
Make sure the main motor has been lubed at its bearings.
Lastly, resurface the capstan idler, and make sure the adjustment is good. Look at the TC-270 service manual for the adjustment.
Tom

nexar's picture

Sony TC-277

Hi Tom
I have taken this thing pretty well apart, and lubed everything. I had the flywheel out and lubed it with lithium grease, as well as everything that slides.
The tape counter is froze up, so I disconnected the belt.
I adjusted the drag on the supply reel..The capstan idler is good to go, and the pinch roller has good pull.
The only thing I didn't think of you mentioned is lube the motor. It could have a dry bearing, but by looking at it, it could be quite a job.
I just hope it is not an electrical problem somewhere. Someone mentioned on another forum about the cap that feeds the motor being bad. I would think a bad cap, would be bad all the time,,,that is above my head.
I will lube the motor and see if that is the problem..Thank you for the info. I will post if that solves the problem.
Bob

nexar's picture

Sony TC-277

Here is the update. I oiled the motor, it wasn't as hard as I thought. The speed slowed down again after 30 minutes.
I went to eBay and typed in Sony motor cap, and found one for sale,,here is part of what the listing said:

Do you have a Vintage Sony (some other brands also) reel to reel deck that will not run the correct speed, slows down after running a while, and the motor gets hot to the touch? The motor run capacitor is causing your problems and needs to be replaced. The original capacitors in the units are silver round metal can shaped capacitors. These are a newer more reliable type of capacitor. They are electrically IDENTICAL and work exactly like the old one.

I ordered one and hope that solves the problem. I hope the info you gave, and what I found out will help someone else in the future.
Thanks Tom for your help.
Bob