1985
Betamax SL-F90



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Technical

Pendulum
Pendulum


hall effect sensors with glue
Hall effect sensor attached with glue

Fault and repair guide

Stops in play or record

The first thing to check is that there is adequate torque on the take up spool. If there isn't much then the cause is usually down to two contributing factors.

The first is the drive pendulum which can cease up and the second, and the second more serious factor, is wear on the reel motor bottom bearing. The pendulum is simple to replace but the bearing is moulded into the chassis and replacement necessitates that the entire chassis be replaced. One possible compromise is to fit a small piece of plastic into the bottom bearing to raise the rotor and allow it to move freely. Sony supply a repair kit for this purpose.

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. Full details on how to fix this can be found on the head motor page.

Deck goes into rewind

This can be caused by failure of the tape end sensor. You can check this by unplugging the sensor at its socket on the PCB.

Failure to load a tape

The cassette carriage can fail to operate. This is caused by breakage of the plastic gears in the side of the mechanism. When this happens they have to be replaced.


Quick fault guide

Please click on the link if you are able to contribute a solution to this list. Add a new quick fault guide entry.

If you have a question about this model, please raise it on the chatpage.

FaultSolution
Ever power on but the display change when pulse on/stand by, not load the tapesBefore of this problem played in b/w with some short white lines
I checked the voltages of the power supply in on and in stand by and all was correct except the 12 volts output, pin 9 of IC001 (STK 5441) and pin 2 of CN002 that ever had about 20 volts
I changed the IC001 (STK 5441) and now load and play in b/w with some short white lines

Is rare that the fuses was not cutted and the video was not damage
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