Hi, and thanks for the quick reply. You are right, there are two sensors and a patterned disk under the left roller. I don't know how to check it though. Any suggestions? Also, the player behaves strange sometimes during FF and REV, slowing down and the STOP button stops working. It is possible to stop the tape by first pressing the button for winding opposite direction and then STOP.
If the tach roller on a TSR-8 stops working for some reason, FF and RW don't respond to the STOP button anymore. It doesn't slow down, though. It might be the same kind of thing, the R8 and TSR-8 being different designs.
(EDIT: The slowing-down might also be the tape. Is it new RMGI, or old Ampex stock?)
Checking it is tricky. It could be one of the following:
1. The patterned disk is physically missing. Someone here actually bought a TSR in that condition.
2. The patterned disk has detached and is spinning freely instead of rotating with the roller.
3. One or more of the LEDs has failed.
4. One or more of the sensors has failed.
5. The sensor module has somehow become unplugged in transit, at either end.
I'd start by making sure the disk spins properly and the pattern isn't somehow damaged. The usual arrangement is that it has a cap at the top which unscrews allowing you to remove it.
It's also possible to check the LEDs fairly easily. You'd need to remove the tach roller for this, though. If they're red LEDs you're golden because you can just look at them and see if it's working.
You might need to start the transport, though and it's best if you run it without any tape on the machine.
To do this on a TSR-8, you remove the tape, pull up the right-hand roller (as if it had tape loaded), and the capstan should start spinning. Then you can press PLAY, REW etc.
The R8 is probably similar, if that doesn't work try holding both rollers up - I don't think the R8 has a tape-break sensor like the B77 does, but if it does you'll need to block it with card or something.
Once you've fooled the machine into running without a tape loaded, and with the tach roller removed, look at the LEDs. If they're glowing red, that's good. If they aren't, they might be infra-red ones, which requires a bit more effort.
To check an IR LED, find a video camera with a preview - a digital camera or a phone might do. Check it works by using a remote control - you should be able to see the LED at the end come on in the preview window, when you press a button on it. Not all cameras can see this so you might need to try several.
Assuming you can find something that can see in infra-red, run the machine up with no tape as before, and see if the LEDs are glowing.
If they are both lit up, I'm out of ideas. You might still check the cables in case it's only half plugged in or something, e.g. the sensors are out but the lights are on. After that you'd have to check that the sensor is getting a voltage across it using a multimeter or something.
Checking the cables is self-explanatory, they're usually plugged in with a jumper plug of some kind. You will have to open the machine up to do this, though and that needs advice from someone who's done this on an R8.
