[MacCheetah3]

Hi
Normally a Mac OS will tell you what it changed especially firmware. So if it didn't say firmware updated ............You have to restart and hold in the programmers button when to do a firmware update. So I highly doubt it did anything with your firmware unless did you update your firmware prior to installation? Have you tried the normal like PRAM reset, Extensions off, or starting from a cD? If all else fails find the CUDA Reset for your model and reset the logic board and power supply board with it.