Help with a Revox PR-99 - Won't play with tape...

[Tedri Mark]

Hi there,

I have a PR-99 which seems to function as expected without having tape threaded, but when I press play with tape in, it clicks, moves all the rollers and tried to take up the tape but it can't.

If I use my finger to stop this roller from pinching the tape, it reels the tape through as expected, but I'm assuming the purpose of this roller is to squash it against the other one which feels like some sort of flywheel, to keep the rate of tape steady, yes?




Any ideas?

Thanks,

Mark

 

[mdainsd]

Is the small metal one in the two you circled spinning on its own? Its called the capstan.

 

[jpmorris]

If it's like the B77 (and I'd be amazed if it wasn't) the capstan - the metal post the pinch roller presses the tape against - should start spinning as soon as the machine is powered on. If not, you have an internal problem of some sort.

 

[Tedri Mark]

Is the small metal one in the two you circled spinning on its own? Its called the capstan.

Ah... Nope, that's not spinning.. Hmmm...

I see on ebay you can get kits for replacing the capacitors relating to the motor, with images of leaking capacitors, Might open mine up and see if there's anything obviously wrong on mine..

The thing is, with it being an unknown unit, whether it's worth trying to fix or not...

Cheers, for the help, I'll keep you posted..

 

[jpmorris]

The Revoxes are direct-drive so there's no belt, otherwise that would be the first thing to check. If the reel motors are operating it's not going to be the fuse.

Simple things first - make sure the capstan motor is plugged into the capstan controller. Make sure the Hall sensor is as well. Make sure the capstan controller board hasn't come loose, since it is plugged into some other board in turn.

Studer's FTP site has a complete set of technical manuals in PDF form, so I would grab a copy of the service guide, and that should give you some idea of what connects to what.


EDIT: On the subject of capacitors, you might try turning the capstan manually and seeing if it starts moving by itself. That might indicate a bad starting capacitor.

 

[Tedri Mark]

I think I have the service manual already, so I'll have a look.

When I spun the capstan it seemed to carry on to a degree, which is what made me think it was some sort of flywheel rather than a motor, so after checking the simple things I'll take a look at those capacitors..