I seem to be having some sort of problem with my extruder board. I blew my old board's Channel 2 (channel 3 never worked anyway) because I accidentally let my thermistor send power to my PWM section (I was curing a new heater barrel). Fortunately I had a spare kit which I built up.
I installed the bootloader, and even tried the test program on the reprap board which ramps up the various parts. It worked perfectly. Ok, then I installed the firmware (I tried both 1.1 and 1.2 and had the exact same result). Ok, now the new board seems to work a little bit, I can turn the fan channel on and off, and the mosfet works too. But when I use them they seem to be very sluggish and slow. The heater channel doesn't work at all. I was one 5003N chip short (I tried to fix the old board with it) so channel 3 isn't completed, though I never was going to use it anyway.
In replicatorg, the error message "payload not big enough" appears constantly, and the temperature is set to 0 permanently. When I plug in the old board, the error goes away and it works perfectly fine (apart from the blown channel). Any ideas whats causing this problem in the new board?