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About Rick Montgomery
Expertise
Most questions about 1970's-1980's audio equipment. Most 1980's -1990's VCR's and VCR combo's. Most 1980's-1990's car audio, except original equipment. I know name brand after-market such as Kenwood, Pioneer, JVC, and some Sony. I am not so good with TV's, DVD's or camcorders. I do not work on Projection TV sets at all. I also have no access to documebntation for sets outside of the United States.

Experience
Professional Electronics Technician since 1975, specializing in most audio, home, portable and car. Also all VCR's. Limited TV knowledge. No projection TV experience

Organizations
Through work, NESDA.

Publications
n/a

Education/Credentials
High School. Graduated with 2 yrs Vocational Electronics in High School.

Awards and Honors
Certificates of completion of factory training seminars for various brands

Past/Present Clients
Thousands of customers to the Service Centers I have worked for.

You are here: Experts > Home/Garden > Home Appliances > TV/VCR/Stereo Troubleshooting > JVC HR-S4700 VCR REPAIR

TV/VCR/Stereo Troubleshooting - JVC HR-S4700 VCR REPAIR

Expert: Rick Montgomery - 11/9/2009

Question
Rick,

Thankyou for all the info you have supplied to me concerning the JVC HR-S4700 machine that I am trying to repair. I have since, replaced the following components:
1)Clutch
2)ACE Heads
3)Tension Arm & spring (spring was the only variable)
4)Erase Head
..... Other components that have already been changed:
5) Pinch Roller
6) Moving Mechanism Motor
7) Belt for Moving Mechanism Motor
8) Mode Switch
9) Idler Gear Wheels
10) Capston Drive Belt
& 11) Exchanged Capston Motor From Newer German Machine

----   I noticed one more thing concerning the Capston Motor:
  I observed that when the pulley wheel of the Capston Motor was turning during playback, it appeared to be squashed, so that it would give its widest diametral dimension every 180 degrees, causing the drive belt to waver outwards slightly. I can only assume that the machine was unused for a long period and this small pulley wheel was in the same position under pressure from the Capston Drive belt for a long time and this may, over time, have squashed the plastic in this axis. I have ordered a Pulley kit but wondered if you could give me some advice on the following:

1). Will it be possible to lever off the old Pulley belt without damaging the capston motor.
2). I have been told that one needs a quick drying cement to attach the new pulley wheel - would this be a super glue or a two part quick drying glue containing an adhesive and a hardener.
3). When I playback recordings made on this machine on other vcr players, I notice that the audio tracking clicking noise cycles in and out from quite loud to nearly disappearing but I can never completely silence the tracking click noise, even though I have adjusted the ACE head positions of two other machines but this has made no difference - could the distorted capston pulley wheel be causing this symptom (ie affecting the timing).

   Regards,

    Rod Whitehouse.
    --------------

Answer
Rod,
  I do not understand your terminology with "lever off the old pulley belt". I am familiar with the kit you are referring to, but these were only replaced if the pulley split and lost torque due to not having a snug fit on the motor shaft. It should pull right off. Your kit will come with 2 pulley's. be sure to use the correct one. As for the adhesive, no, I do not recommend super glue or epoxy. I have found that contact cement works best.
Your belt and pulley have teeth as I recall. The uneven spacing of teeth over the split on the pulley would be causing the clicking.
regards,
Rick

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