I dont i have mine turned almost all the way in so it is set to 200 how did you bypass the switch with a jumper on the switch contacts or somer were else.
Low_SST
+1y
use a DMM and check for continuity, this way you can know where the circuit died.
frmlayin
+1y
Sounds like the contacts broke on the switch try switching to the other side if not get a new switch