Madhu,
I had a similar problem with a CNC milling machine.
After 2 weeks of service technicians' time, swapping every circuit board,
replacing virtually every driver transistor, and swapping stepper motors,
testing my boards in a known good machine, we all finally gave up and I retrofit
an aftermarket controller. Quite frankly, it was the best thing I could have
done as I now have virtually unlimited memory capacity (the old one could only
run 650 lines of G-code) and true 3 axis (up to 4 axis) simultaneous movement
(the original was maximum 2 axis simultaneous). The cost was under $10K
and the PC is "off the shelf" so it's very easy to maintain.
If you'd like to discuss this in more detail,
please feel free to contact me directly.
Regards,
Ed Popielarski
QTA Machine
10 Mc Laren, Ste
D
Irvine, Ca. 92618
Phone:949-581-6601
Fax: 949-581-2448
Cel:
949-337-2578