It frequently, but not always, shows jam @ lower cassette - tells me to open the right bottom door (no error codes) - after a few sec (5-10) I power up the machine. At times it begins to function ok, but usually after overnight shutdown and then pwr up it shows jam. I removed lower feeder, cleaned all the sensors. No go. Problem is erratic, not constant. LV power supply? Bad/flaky sensor? They have steady 115V in their power line.