Quote Originally Posted by aldoo View Post
Hi, I have a lathe EZ Path I of Bridgeport from 1991. Actually we have troubles with the driver. We have the Driver Fault Alarm. When we check it the intern fuse was blown, we changing it, but when turned on the machine three mosfets was destroyed and the fuse too. We changing the fuse and compatibly mosfets, conecting the drive without the motor armature, tachometer and encoder with the supply all ok, but when connecting the tachometer and encoder without motor armature the new fuse and the three mosfet blowed again.
We do not know what is happeing. Some one have had this trouble? or maybe some one have the electronic diafram of the driver?
I attached some images of the driver.
Just a general power MOSFET note:
When MOSFETs fail they almost always short their Gate to the Source or Drain (most often both)
This tends to destroy the gate drive circuitry so simply replacing the MOSFETs without checking
that the gate drive circuitry is working is liable to result in more fireworks...