Betamax PALsite: SL-F1 : Technical

SL-F1

1983

Technical

Camera Socket

The 14 Pin Camera socket is known as a Sony K-connector. Details of the pin connections are available online.

Multi-Connector

The 8-pin Din Connector is known as a Sony Multi-connector and carries a comined Audio, Video and Remote contol ( later known as CTRL-S ) signals. Details of the pin connections are available online.

Fault and repair guide

Tuning problems

There are sometimes problems with the SL-F1 tuner failing to lock on to a TV channel. The first thing to try is to switch off the AFT. This is to cater for the case whereby it is not locking onto a signal due to a NICAM sound carrier throwing it off.

Failing that, it sounds like a fault, the problem is possibly that a fuse has gone. These though are very small circuit board (silicon) fuses. They are small components labeled f-1, f-2. If you have a meter and can find them it is possible to test to see if they have blown. This is quiet common on the F1. The first fuses to test are the ones nearest to the metal can (ie the DC to DC convertor).

Irregular tape transport during rewind/review.

This is cause by the tape which sticks to the upper drum when it is worn. It can be fixed by replacing the upper drum. Sony now supply an improved type which is made of a harder wearing alloy.
The diagram opposite shows the new upper drum which no longer has a mounting plate

Grating noise during tape threading/unthreading.

This is caused by a split threading gear. Sony now supply an improved type which does not contain the inside metal bush. In the original design this would expand and cause the plastic to crack. It is also advisable to replace the threading belt at the same time.

Machine appears dead.

The circuit protectors in the secondary power supplies are common to failing. Check the one near the centre of the bottom PCB first. If all fuses check out OK then suspect failure of one of the micro processors. These are surface mount components and are difficult to replace.

Tracking noise bar across picture.

With older machines it is not unknown for the capstan servo lock to drift slightly. This can result in what looks like a tracking noise bar permanently across the picture. The cure is to readjust the capstan bias.

No head drum rotation

You may find that the head drum fails to rotate. This is due to a problem with the Hall effect device on the head drum motor which is secured by a blob of glue which tends to become conductive especially if it absorbs moisture. The best remedy is to remove the glue from the device. To do this first remove the rotor from the bottom of the drum by undoing the lock-nut. Sometimes, however, it is enough to wait for the damp to dry out.

Erratic operation

Over time, this ribbon connector is prone to fracture causing erratic behaviour of the VCR. Symptoms include random operation of machine functions or loss of audio. Also pressing a button can get no response or a strange response.

See also the ribbon connector parts page.

Quick fault guide

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Fault Solution

Not unlacing tape. Check the unlace end sensing switch then Q611 and Q613 the unlacing end sense switching transistors on the system control panel

Drum running fast supply reel spins in reverse/foreword search Check switching transistor Q204 in the system control for short circuit

Intermittent or no colour in playback and record. Modification: change R104 & R106 to 820ohms on panel 5F6

No or poor sound in record mode. Check condition and setting of coil LV001 on panel LS8 if fault persists check coil L14 for failure

No operation via battery. Check fuse FB01 & zener diode D810 & diode D811

No picture in playback or record. Check fuse FS04 on panel MA3 for failure

No playback. Check the pinch roller is engaging if not check the lever coupling between the roller and solenoid

No playback picture. Check for failure of 1C4 BX10221 on the SF5 panel

Rewinds at high speed in response to pause. Check IC203 TC40813P for failure

That clunky, twangy sound on rewind/f.fwd See my fix under SL-C9

channel buttons on ttf1 stuck and not responding If you have stuck channel 1 - 12 buttons on your ttf1, this solution works. Remove top, bottom and front panels, and unscrew the hh1 board from the front fascia. use a needle and drop one or two drops of light plastics friendly oil (model railway gear oil is what I used) and drop one drop per micro switch between the button itslef and the barrel of the switch. Leve to soak in for a few minutes and then gently try to work each microswitch up and down until they are all free. Reassemble your f1 and try again the 1-12 buttons. If after first attempt strange behaviour is still seen from the buttons, apply one more drop each and work the switches free some more. I had to do this twice to fully cure the problem, but now all is well again.

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