Nad 6100 Cassette Deck plays a few seconds just fine then stops

It’s probably a dead spot(s) on the cam motor (corrosion/from sitting idle for long periods), or the back tension belt needs to be replaced. Both can be an easy fix.

To free up the dead spot on the motor, take a sacrificial cassette and remove all the tape inside, just pull it out and discard, just leaving the reels inside to make a “dummy cassette”. Put the tape inside the deck and press play, let it run overnight or 24hrs. Next day try a regular tape and see if it plays.

If it still doesn't work replace the back tension belt. To access it, remove the cassette door (slide upwards), and the back plate (2 screws) in the cassette well and you will see it there to the left. MARRS sells an exact replacement.

If if it still doesn’t play, then the cam motor needs to be replaced. You may need to find a donor deck, I believe the Nakamachi BX-300 uses the same transport. But it it wold be more cost effective to find another NAD deck.

Thanks for all of this info. I can report back now that I belt a belt from Germany and with the help of a kind soul who guided the process, I changed the belt and pinch roller. I also used a 9 volt battery to get around the dead spot and the deck will ff and rew, but will just click about 5 times and stop totally when I push play. I then have to turn it off and then on again for anything to work and still same. Does this suggest it is the cam motor or the reel motor? I am not sure about the clutch, but will keep looking - not sure of proper names and which is the uptake side, but will investigate. Thanks for the help! I so want to get this working!

Just a note added, late: I bought a nonworking 6100.  No FF, RR, or play, but seems electrically OK, lights, etc..  After using electronics cleaner spray in the two motors, mechanism, and buttons, then relubricating it, it will smoothly FF and RR.  Play function, like yours, still only clicks a short time via its motor, then all goes quiet.  Additionally, the transport roller+heads are on a moving subchassis; it's supposed to be raised up (by a servo or gear) into contact with the capstan and tape when Play is pressed.  But mine doesn't.

I will replace the flat belt, and try to ensure that the Play contacts are clean.  Once that's been tried, I'll add more to this post.  
Thanks,
Rick

Take a look at the tape counter. Its common (and not saying that this deck was done this way) that if the tape counter stops moving, the machine automatically stops. This is done to prevent it from eating tapes.


The symptom is that of the take up spindle not turning. Its supposed to have a certain amount of torque, if not it won't be able to take up the tape from the capstan. So the machine stops, since quite often the tape counter is belt-driven by the take-up spindle.

The most common reason for this is that the tire on the spindle has hardened. If this is the case, the spindle will have to be removed, which can be a bit tricky. Its likely held in by a tiny circlip. When removing the spindle, keep track of all the tiny nylon washers! There's probably one under the circlip and one or two beneath the spindle.
Replacement tires are available from Russell Industries on the east coast. www.russellind.com  You'll have to dig through their catalog to see if they have one that fits. Good measurements are going to be important if they don't show an exact replacement in their guides. Good Luck!

Progress!  That is, enough progress to be hopeful, but not there yet.  My 6100 deck's no-play problem was due to a loose flat belt on the combined mechanism that provides both play-spindle rotation and roller rack positioning.  I was able to test this via a bit of rubbery subterfuge, which quickly gave out.  At the moment, I've unmounted the tape mechanism loosely to get some leeway to work, but it's still the devil to wind the new belt into place with only two hands.  By tomorrow I should have this running; will report again then.