On 2010-08-29, Jon Elson wrote:
Ignoramus5734 wrote:
Since yesterday, I had the Z axis behaving very weirdly, suddenly lots
of chatter and vibration, extremely erratic behavior, then no motion
at all, then some motion etc.

Attempting to diagnose it (isolate the issue) pointed to a servo drive.

Since I have several additional drives on the shelf (they were cheap),
I swapped one for another. Now the Z axis is back to working. I opened
up the drive that I relpaced and saw one chip blackened.

Not sure what to make of this.

i

Whose servo amp? Can you tell by location what that chip is connected to?
Check another to get the part number of the burned chip.

That was am AMC 30A8 amplifier, revision T.

The chips on them mostly do not have markings, this one was a small
one in the middle of the motherboard.

I really like the drives, their simplicity, cost and support from
AMC. I do not know if I can guess the cause. But, possibly,
interference again is to blame. I have, since, routed the twisted DC
motor cables away from control stuff.

You mentioned ferrite cores to place on these cables. Would you
suggest any particular Digikey part number?

Thanks

i