If the problem happens with tape threaded, it could be reel tension. The outgoing tension idler operates the micro-switch that turns off the transport. If the take-up reel tension is low, the idler will momentarily relax immediately after pressing play as the take-up reel comes up to speed and the transport will shut off.
I own a 1520 and have the service manual for it. You are welcome to ping me off list for further assistance, if needed.
Corey Bailey Audio Engineering
From: carlstephenkoto <[log in to unmask]>
To: [log in to unmask]
Sent: Saturday, November 3, 2012 2:17 PM
Subject: Re: [ARSCLIST] Technics RS-1520 reel-to-reel recorder
The first thing you need to find out is if the Technics does this without a tape threaded. Also, if this symptom occurs at all speeds.
In either case, there are a number of possible problems. A fairly common one is a failure of one of the IC's on the control board. On the "easy fix" end is that it's the result of playing sticky tapes where residue from tape binder failure is stopping the tape travel (where thorough cleaning of the tape path is needed).
I've repaired a number of these machines and while some of the solutions can be quite simple for the end user to fix him/her-self, finding the root of the problem can take a bit of Q&A.
I suggest that you have your friend register and post an inquiry to the Tape Project Forum. There are a great number of Technics RS series users there and I can help him to get the 1520 up and running and the thread will add to the troubleshooting data base there.
On Oct 24, 2012, at 1:43 PM, Jim Long wrote:
> Another person contacted me recently about his 1520, having found from a
> 2008 post I made to the listserv that I had a 1520 and both its Operating
> Instructions and Service Manual. His symptom is that after hitting the play
> button the unit starts to play but then stops virtually immediately. On page 6
> of my manual, there is a Symptomatic Check List. The closest thing to the
> symptom described to me is "tape stops running during playback" with the
> "check point" of "too strong a pressure between pressure roller and capstan,"
> noting that a "pressure roller pressure adjustment" is needed. Pages 14-15
> describe the process by which the pressure can be adjusted to 900 +/-100
> Does anyone have a hands-on familiarity with the 1520 to add any further
> comments/warnings/encouragement regarding this symptom? I will pass on any
> info received. Thanks!
> Jim Long
> Baroda, MI