Sony SL-200M MKIII Betamax VCR Problem - UK Vintage Radio Repair and Restoration Discussion Forum

mahmoodi · 21st Oct 2019, 7:29 pm

I pulled the VCR from the storage room , it worked once only and then this problem occurred.

https://www.youtube.com/watch?v=0FBeWDVQbNA

3Phase615V · 22nd Oct 2019, 2:51 am

Hi,

You say it worked once, then failed. Just to be clear, I take it you mean the VCR powered on normally, accepted a cassette, i.e. fed successfully through the loader, played or whatever, then ejected without any problems?

Not being familiar with Sony Betamax machines, I couldn't tell from quite a bit of background noise in the video whether the VCR has a motorised loader mechanism which was trying to load the cassette and failing. I presume the loader usually "grabs" the cassette and feeds it into position, in which case I would imagine that the mechanism has got stuck somewhere along this sequence. Assuming it's been in storage for some time some of the lubrication may have turned a bit toffee-like and caused the jam. I'm not sure how this could affect the power/standby button function, however, but perhaps a sprung electrical contact used in the mechanism is in the wrong position (on or off) and preventing the power button from starting the shutdown sequence. In any event, my attention would first focus on the loader mechanism to see what's blocking the cassette to see if I could help free it. After a few tries of loading and unloading a test cassette I would hope I was able to see where the mechanism was jamming. It may even be the case that with repeated use you end up clearing the jam and making it less likely to recur but I think I would be looking at giving the mechanism a service to try to prevent any future jam recurrences.

Actually, having watched your video a couple of times I see that the VCR appears to think it has a cassette loaded as the take-up reel is spinning at playback speed without a cassette in position. When you ejected the cassette the first time did it eject completely successfully or did you have to open up the VCR to pull it out?

dj_fivos_sak · 22nd Oct 2019, 2:56 am

This chassis (711B3) has a rotary mode switch on the back of the mechanism, just like most VHS machines. Make sure it's clean. This video might help you:

https://www.youtube.com/watch?v=sdslPoYJSIY&t

3Phase615V · 22nd Oct 2019, 3:12 am

Quote:

Originally Posted by dj_fivos_sak

This chassis (711B3) has a rotary mode switch on the back of the mechanism, just like most VHS machines. Make sure it's clean. This video might help you:

https://www.youtube.com/watch?v=sdslPoYJSIY&t

Good video, well suggested. I think I would go with that if it were my issue.

mahmoodi · 22nd Oct 2019, 10:18 am

Quote:

Originally Posted by 3Phase615V

Hi,

You say it worked once, then failed. Just to be clear, I take it you mean the VCR powered on normally, accepted a cassette, i.e. fed successfully through the loader, played or whatever, then ejected without any problems?

Yes Exactly ..

When you ejected the cassette the first time did it eject completely successfully or did you have to open up the VCR to pull it out?

it did eject completely , and stopped accepting the tape for the next time ..

mahmoodi · 22nd Oct 2019, 10:24 am

Quote:

Originally Posted by dj_fivos_sak

This chassis (711B3) has a rotary mode switch on the back of the mechanism, just like most VHS machines. Make sure it's clean. This video might help you:

https://www.youtube.com/watch?v=sdslPoYJSIY&t

I did watched this video , and did clean the rotary switch , it cannot be open to clean it well , but I tested with multimeter its working fine , I am concerned about the power switch why its always ON , also I test the switch by multimeter and its fine ..

dj_fivos_sak · 22nd Oct 2019, 12:12 pm

Does the power supply have an STK voltage regulator IC or is it of a switching type with a TL494CN IC? In the case of an STK module, check that for failure. But the unit might not be able to power off if the mechanism is stuck and the system control circuit is preventing the system from powering off. But I might be wrong on that since I've never actually have had this model nor I have a manual for it.

Fivos

mahmoodi · 22nd Oct 2019, 3:20 pm

Quote:

Originally Posted by dj_fivos_sak

Does the power supply have an STK voltage regulator IC or is it of a switching type with a TL494CN IC? In the case of an STK module, check that for failure. But the unit might not be able to power off if the mechanism is stuck and the system control circuit is preventing the system from powering off. But I might be wrong on that since I've never actually have had this model nor I have a manual for it.

Fivos

It have the STK7217 but all outputs are ok , 12v , 5v .. I think as you said the problem is from the mechanism somewhere .

21st Oct 2019, 7:29 pm	#1
mahmoodi Diode Join Date: Aug 2019 Location: Dubai, United Arab Emirates. Posts: 8	Sony SL-200M MKIII Betamax VCR Problem I pulled the VCR from the storage room , it worked once only and then this problem occurred. https://www.youtube.com/watch?v=0FBeWDVQbNA

22nd Oct 2019, 2:51 am	#2
3Phase615V Tetrode Join Date: Nov 2011 Location: London, UK. Posts: 90	Re: Sony SL-200M MKIII Betamax VCR Problem Hi, You say it worked once, then failed. Just to be clear, I take it you mean the VCR powered on normally, accepted a cassette, i.e. fed successfully through the loader, played or whatever, then ejected without any problems? Not being familiar with Sony Betamax machines, I couldn't tell from quite a bit of background noise in the video whether the VCR has a motorised loader mechanism which was trying to load the cassette and failing. I presume the loader usually "grabs" the cassette and feeds it into position, in which case I would imagine that the mechanism has got stuck somewhere along this sequence. Assuming it's been in storage for some time some of the lubrication may have turned a bit toffee-like and caused the jam. I'm not sure how this could affect the power/standby button function, however, but perhaps a sprung electrical contact used in the mechanism is in the wrong position (on or off) and preventing the power button from starting the shutdown sequence. In any event, my attention would first focus on the loader mechanism to see what's blocking the cassette to see if I could help free it. After a few tries of loading and unloading a test cassette I would hope I was able to see where the mechanism was jamming. It may even be the case that with repeated use you end up clearing the jam and making it less likely to recur but I think I would be looking at giving the mechanism a service to try to prevent any future jam recurrences. Actually, having watched your video a couple of times I see that the VCR appears to think it has a cassette loaded as the take-up reel is spinning at playback speed without a cassette in position. When you ejected the cassette the first time did it eject completely successfully or did you have to open up the VCR to pull it out? Last edited by 3Phase615V; 22nd Oct 2019 at 2:59 am.

22nd Oct 2019, 2:56 am	#3
dj_fivos_sak Heptode Join Date: Mar 2015 Location: Lefkada, Greece Posts: 969	Re: Sony SL-200M MKIII Betamax VCR Problem This chassis (711B3) has a rotary mode switch on the back of the mechanism, just like most VHS machines. Make sure it's clean. This video might help you: https://www.youtube.com/watch?v=sdslPoYJSIY&t

22nd Oct 2019, 12:12 pm	#7
dj_fivos_sak Heptode Join Date: Mar 2015 Location: Lefkada, Greece Posts: 969	Re: Sony SL-200M MKIII Betamax VCR Problem Does the power supply have an STK voltage regulator IC or is it of a switching type with a TL494CN IC? In the case of an STK module, check that for failure. But the unit might not be able to power off if the mechanism is stuck and the system control circuit is preventing the system from powering off. But I might be wrong on that since I've never actually have had this model nor I have a manual for it. Fivos