JCM2000 TSL footswitch problems


I just got a Marshall TSL 60 head and am having trouble with the footswitch.

Of the five buttons: Clean - Crunch - Lead - Reverb* - FX Loop*

The Reverb and FX Loop are both latching switches and work fine. The Clean, Crunch and Lead switches are all momentary and there's some sort of digital logic switching going on on the board. The problem is with these switches.

When I turn the amp on, the Clean switch LED comes on. When I hit the crunch or lead switch, nothing happens (No LED, no change from clean).

I thought it was an issue with the switches, so I replaced them. Now Crunch and Lead still do nothing, but when I hold down the Clean it switches to Overdrive for as long as I am holding the switch. When I let go, it goes back to clean.

Anyone have any thoughts why the switches aren't doing their job? Could it be a fried transistor that's supposed to be controlling the logic switching that's going on (Anyone know a good way to test this?). Some more info on the footswitch...


[DIN Pin Guide](http://i81.photobucket.com/albums/j202/paperboy38375/Forum Pics/tsl100switchinginfo.gif)

[Board Pic](http://i91.photobucket.com/albums/k288/fixr1984/DSCF0946.jpg)

[Another Board Pic](http://i281.photobucket.com/albums/kk224/chrisdrane/TSLInternal_zps056b5334.jpeg)

asked 10 Sep 2016 at 01:31 PM

David Burke
Answers: 1


Hello David,

The fault could be with the socket on the pcb in the amplifier or the lead itself breaking down. We would suggest if possible to try another footswitch if this is not possible the logic circuit would need to be traced to see which part is faulty as though we have had very few problems with the logic circuit on the TSL.  Therefore we would recommend that you have an engineer check the circuit in the amplifier and footswitch, if you would like us to look at it for you then please contact jgreen@marshallamps.com. 

answered 12 Sep 2016 at 07:33 AM

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