Sanyo VCR4400 Betamax doesn't play tapes

[ESigma25]

I did a bit more maintenance tonight, including cleaning the various pinch rollers and tape guides and cleaning and greasing the reels, which stopped the tape eating and improved the unwinding, but when you press Play the right reel (the take up reel) still does not turn. I notice it has some kind of sensor underneath, maybe that sensor is dirty? This particular problem is very much new to me.

[JohnCT]

Originally Posted by ESigma25

... but when you press Play the right reel (the take up reel) still does not turn. I notice it has some kind of sensor underneath, maybe that sensor is dirty?

Speaking in general terms because my brother was the Beta expert.

Sensors under the hubs are usually dual element opto devices (trans and receive) and the underside of the hubs usually have a reflective surface plated onto the plastic. Sensor failures won't stop the hub from turning initially, but will cause a shutdown if the sensors detect no movement within a programmed window.

Usually, the idler tire is the problem when reels don't act right. A new tire will improve grip, and sometimes taking apart the clutch pack it's attached to and stretching the spring a *wee* bit will improve torque. Too much stretch and it will pull the tape through the capstan and stretch it.

Also, the transport may be experiencing an incomplete load. It may look like the guides are full wrapped around the heads (and they may be), but often the large cycle gear has to rotate another few degrees after loading to satisfy the position encoder, which is another troublemaker.

John

[ESigma25]

Originally Posted by JohnCT

Speaking in general terms because my brother was the Beta expert.

Sensors under the hubs are usually dual element opto devices (trans and receive) and the underside of the hubs usually have a reflective surface plated onto the plastic. Sensor failures won't stop the hub from turning initially, but will cause a shutdown if the sensors detect no movement within a programmed window.

Usually, the idler tire is the problem when reels don't act right. A new tire will improve grip, and sometimes taking apart the clutch pack it's attached to and stretching the spring a *wee* bit will improve torque. Too much stretch and it will pull the tape through the capstan and stretch it.

Also, the transport may be experiencing an incomplete load. It may look like the guides are full wrapped around the heads (and they may be), but often the large cycle gear has to rotate another few degrees after loading to satisfy the position encoder, which is another troublemaker.

John

For now I'm going to try getting a new upper idler tire and see if that helps, I think the playback was stopping because the take-up reel wasn't being engaged.