Troubleshooting Ampex ATR104

Hi everyone!
I have an ampex ATR104 here, picking up dust and I want to revive it.
I has parts missing that went into the ATR102, at least the capstan tacho disc is missing.
I'm trying to get a replacement but in the meantime I'd like to estimate if it needs more work or not, so any help is appreciated!

Right now when it switch it on, the motor starts winding crazy and nothing stops it, could that be due to the missing tacho disc or is it the transport that's going wild?
On the control panel I can't switch the tracks to input, they are stuck to repro, should this be independent from the motor running endlessly? Is the remote broken as well?

If anyone ever experienced that I'd greatly appreciate any tips and hints.
Thanks everyone!
Jules

Hi Jules

Are all the boards present in the card cage?

It sounds like the transport control board may need some tlc. I don't think the missing tach wheel would do that.

Verify that all your PS voltages are correct.

Once you've done that you could try swapping cards with the working ATR to isolate the problem.

If you haven't already done so, join the AMPEX MAILING list.

http://recordist.com/ampex/mail-sub.html

http://recordist.com/ampex/

There's a ton of accumulated AMPEX and tape machine knowledge there.

Mark

Thanks for the quick reply!
I stuck a piece of paper in the optical sensor of the tach unit to stop the motor from running.
The controls still don't work, I'll try swapping cards after I check supply voltages.
I definitely hate non metric allen keys, don't have any here and it's a PITA to disassemble anything I actually pulled out my dremel to downsize metric ones...

You need to load a tape in order for the transport controls to function.

Mark

I haven't tried the transport yet, if the tacho assembly has no urethant disc in the opto element, the motors run like crazy so I can't load any tape.
On the ATR102 I don't need to have tape present to switch from repro to input on the channels and that's what doesn't work on the ATR104.
Close to where the remotes connect there is a long edge card connector ans the connections differ from the 102 to the 104, there might be somthing missing there too...

Right, I assumed you meant Play, Stop, Rec, etc. My bad.

Have you checked to make sure the control cable is plugged in on the right side of the card frame?

There should be a large multi-pin cable with a large metal connector that plugs in to the back connector of the control block under where the system identification label is.

There are also two smaller cables with blue tuchel like connectors that should be connected together.

Mark

Check the motor drive transistors underneath the deck plate.  Somebody may be shorted.
Best,
Bruno2000

runaway motor = shorted transistor. buy a lot of them. they go frequently. a very high strung machine.

j.frad said:

I stuck a piece of paper in the optical sensor of the tach unit to stop the motor from running.

Click to expand...

If the motor stops when paper inserted = NOT a shorted drive transistor.

However... they do fail on those machines, so spares should be an essential fixture of your regularly stocked parts.

Keith

Thanks everyone.
I'll try to figure out if this connector is set up correctly.