Hey vince you are right, not only can a former employee reset a parameter to lock out the cpu, but some electrical glitch can also change the value of this parameter. to fix the problem i logged into the system using hyperterminal, then i was able to access all of the parameters. I compared these with a known good unit and found two parameters UI LOCKING ENABLED, and ENABLE UI ALWAYS. on a good unit, the value of the parameter was 0, on the bad unit it was not 0. after changing the value on both of these parameters to 0, and recycling the power, the cpu now functions normally. on another note, the door operator is a worm gear. Not being very mechanical, i had to replace the worm gear drive unit after one had snapped in half, I had a hell of a time getting that baby back in operation, does anyone have any procedures on how to set up the cable back into the drum sheave. I could not find any info anywhere, and after hours of trying this and that, i finally go the damn thing to go on right, at least it opened and closed when i was finished, although i still do not like the outcome of it. i know there is an easy way, i can not tell you how frustrate i was trying to get that damn cable on. good thing i know something about electricity, got to love those repair guys.