Series 1 BOSS 5 X Axis Dead, still dead after new transistors
I accidentally fed my 2" face mill into some HRS at 60" per minute. My X axis stopped dead in it's tracks as soon as the face mill hit the stock. I tried jogging and it did the jumpy vibration thing like an output transistor was blown. I shut down for the night. The next day, I checked the fuse for the X axis and it was blown (FU12). I replaced the fuse and tried again. Same problem. Then I measured x axis phase voltages at the control and noticed one leg (X4) was significantly different from the others and the known good Y axis motor. I traced X4 back to the lowest transistor on the X heatsink. I replaced only that transistor with a new 2N6547. This did not fix the problem. I then replaced the remaining 3 transistors and still not fixed. I tried swapping SMD boards and the problem stays on the X axis.
By not replacing all 4 transistors at once could a remaining bad one blow the new one?
What else is there that would give me the symptom of a blown transistor?
What else can I check?
Thanks
Matt
