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Nakamichi BX-1 Sankyo Motor Problem

Nakamichi BX-1 Sankyo Motor Problem

I just got a Nakamichi BX-1 Cassette Deck and this Model has got a Idler Clutch which is making the Rewind and Fast Forward and also the PLay Function making to work ! The Idler Clutch is driven by a Sankyo Motor behind it in the middle of the drive. This motor seems to be dead,bacause it does not turn at all. That's why the BX-1 does not get any of the Functions running. There is a lot of Information on the Net and You Tube Videos and all kind of talk, but nobody has come on the point about the reel motor ! What is the Voltage of this Motor. The Capstan Motor is a 12V. I know this because I went into a Multi-Meter Check yesterday. On the reel motor I did not get any Voltage on the Meter ! On the other side the Connector which is plugged into the Circuit board pin-connection is moving the switches sso you can hear it.

Does somebody know this Sankyo Reel Motor Problem and the Solution or Cause to it ????????????

Best regards


Re: Nakamichi BX-1 Sankyo Motor Problem

Stonesfan hints to another typical NAK problem, the cam motor which is responsible for lifting tape heads: When the collectors are "dirty" cam motor won't work, tape heads are not lifted and drive will not start at all. But this is NOT the problem here.

The problem we are dealing with in the BX1 is another one: reel motor is okay, but does not get any power. So Play starts (tape heads are lifted), but right reel is not turning, thus deck's logic circuit will stop again.

I checked this with a BX1 myself. Winder motor is a 6V Sanyko.

FF / Rew should be 6,7V when defective 10-15mV
PLAY should be 2,0V when defective 10 mV

Have a look at the mainboard where cables from winder motor are connected.

There is a heat issue with big resistor R628 getting so hot that it unsoldered itself, and sometimes solderering points of nearby 2SD1664 transistor Q623 are affected, as well. Resolder and voltage of winder motor will be fine, again.

Re: Nakamichi BX-1 Sankyo Motor Problem

Good Morning ! I have already done all the possible work on the BX-1. A brand new Idler-Tire with perfect fit was instaled. The Capstan belt + the Counter belt are in. Heads+pinch roller are cleaned. Using the Multi-Meter I had 12V on the Big Capstan Motor and when I press Play the Motor is turning perfectly and the Heads are coming up smooth. But the Reel Motor (Sankyo) with the rewind and fast forward clutch on it does not react at all. Was trying to get Voltage on the Meter but there was zero Voltage on the Display ! The Reel Motor is also operating with the play Function ! In the Net there is a lot of Information but no solution to that Problem. The Sankyo Reel Motor Problem is an Issue but what is the Solution. Talking about C606+C607......but C means Capacitors ! Why are they talking about a Fuse Resistor or Transistor Problem ??? The wires from the Reel Motor are going to the Plug on the Circuitboard into a Conector with other wires from the drive. They all look good. No damage on the wires !
Best regards

Re: Nakamichi BX-1 Sankyo Motor Problem

if you are not getting any voltage reading across the reel motor, it means it's not getting any power. That means that the motor is probably ok, but the circuit that's feeding it power isn't.

The cables may be OK - as you say no damage to them or connectors - but it's possible that a fuse is blown or the driver transistor that's providing power to the motor is gone. Or a capacitor that's connected to the rail power that feeds that motor is short.

Re: Nakamichi BX-1 Sankyo Motor Problem

I did not put the Nakamichi BX-1 together yet ,so that's why I have a picture of the cleaned front !

Re: Nakamichi BX-1 Sankyo Motor Problem

Hi, unlikely it's a reel motor problem causing no functions. Does the head block go up when a cassette is inserted and play pushed? If not the issue is probably the mechanism motor is stuck. As I recall it is on the top right of the transport looking from the front. Don't take the motor out!!! Try giving the white gear a push with a small screw driver. Since you have a volt meter check across the motor leads when play is pushed.
If there is voltage for a second or two and no action from the motor then it is stuck and will likely start to function when you turn it a bit by hand. good luck and have fun!

Re: Nakamichi BX-1 Sankyo Motor Problem

I know this is very a very old post but I thought I would throw my two cents in if anyone else has this issue.

After repairing several naks decks 2 bx1, 2 bx2 2 cr3a 1 cr2a 1 mr1 1 bx300 and a bx150 here are the most common issues with these decks.

Bx1,2,150, and some 300s. Bad idler tires, control motor not functioning causing the lights In the play and stop to blink and other nice things.

This is caused by the control motor for the mech not to ingage which does not move the 3 leaf swiches for the different modes.

The cause is carbon buildup on the armature because the motor only turns part way never all the way around. The motor can be torn apart and the armature cleaned you could deox as well. Be very careful when taking apart as the brushes are extremely fragile. When putting together don't force in together this will damage the brushes. I believe there is a web site that shows this teardown.

Capstan motor failures are also common.