Is there a wise way to debug a large code?

[HenrikOlsson]

How often is dimmer called? Every hour, every minute, every time thru the main loop?
What if you make it always outout a dutycycle of 200, which is what it's getting set to 18.00 when the problem starts? Perhaps you have a hardware issue?

Also, as a test try to get rid of the "one-liners" and do:

IF Z2=06 THEN
  HPWM 2,150,2000
ENDIF

IF Z2=08 THEN
  HPWM 2,200,2000
ENDIF

/Henrik.