18 Feb
2010
18 Feb
'10
10:04 p.m.
On Thursday (02/18/2010 at 09:53AM -0800), dwight elvey wrote:
On the Siemens drives also used in the H89 and H17, there is an inductor
in series with the +12 to the spindle motor. It's a hash choke that keeps
the motor noise from going back into the +12 rail. When the grease in
the spindle motor gets old and sticky, the motor draws way too much current
at startup (if it ever does start spinning) and toasts this inductor.
It's an exciting failure on the H89, because the "Mission Impossible"
smoke comes out through the drive door and slowly flows down onto the
keyboard. Impressive image, horrible smell.
Chris
--
Chris Elmquist
Finally, assuming it is the problem, what do I need to replace it?
The stripes on it are:
Wide silver (covering one end)
Red
Yellow
Brown
Gold
Thanks,
Bill
Hi
The inductor is most likely a PS filter the analog paths. Although, I'd
measure it in a bridge before replacing it, it is most likely not the
problem you are seeing. As a filter, it is unlikely to cause too much
problems if short, as these circuits are often over designed there.
They rarely are temperature sensitive at the level you are seeing.
If it is not getting hot, it is unlikely to be effected by operation time.
It is more likely something failing in the stepper control. You might
also check to see if things are well lubricated ( no old grease ).