I have a Sony Minidisc deck model number MDS-JB920.
The AMS knob will not scroll through tracks sequentially but when rotated will jump from track 1 to track 6, then 7 and back to 1. This also happens when I try to divide a track and it may jump several seconds or none when rotated.

Red, February 2009

I tried using Servisol Super 10 spray around the shaft. This did not improve things so I once more dismantled the deck and sprayed around where the metal and plastic parts joined and again around the shaft and this time it worked. Thanks for help.

Red, March 2009

Just spray the cleaner down the plastic shaft & around the metal area where the terminals to the board are.It might seem like none has gone in,but it usualy works!
Sorry for not explaining that bit!Hope it all works after.(you can buy a replacement encoder switch)...Gordon

gkshepherdelectronics@sky.com, March 2009

Thanks for answer. I dismantled the deck to gain access to the AMS switch but the switch is a small plastic/metal unit with no openings to spray cleaner in . How do I clean the switch please.

Red, February 2009

The AMS switch encoder is dirty.It just neds cleaning with a suitable switch cleaner spray.Unfortunatly it does involve removing the main cover & front panel to gain access to the front circuit board!If you are confident enough to remove the front board its just a case of spraying the encoder switch.Be careful as you need to prevent any static electricity from being transfered onto this board!!I have repaired numerous units with this fault,this nearly always cures it.Hope this helps...........Gordon

gkshepherdelectronics@sky.com, February 2009