On 12/09/2017 09:14 PM, Brent Hilpert via cctalk wrote: > On 2017-Dec-09, at 6:06 PM, allison via cctalk wrote: >> On 12/09/2017 07:52 PM, Fred Cisin via cctalk wrote: >>> On Sat, 9 Dec 2017, allison via cctalk wrote: >>>> I have several Epson PX-8s and i used them.. They work well with the >>>> various wedges I have. >>>> I also Have a PF-10 which is the portable 3.5" 40 track two side floppy. >>>> The problem is it randomly does not turn the media unless I give it a >>>> push to get it turning. >>>> Things checked: >>>> * Batteries, NEW fully charge (Both). >>>> * internal Power supplies, current voltage and bridged with external >>>> supplies does not help. >>>> * media checked for binding, it does not. >>>> When it turns it reads and writes correctly and at the correct speed. >>>> It may do so without help for many tries then will stop required a >>>> manual push. >>>> At first glance I though there were motor bearing issues but have >>>> verified >>>> this is not so. If I force motor on and restrain it I has good torque >>>> and no >>>> dead spots. All signals in the motor control look good on the scope. >>>> Any thoughts? >>> How does it detect the presence of a disk? and/or disk change? >>> >>> >> Functions normally save for the motor does not always turn on command >> but will if manually pushed. All other functions are normal. > How about a problem with the current supply to the motor, such as low gain in > the driver. > A progressive failure may be just on the edge of supplying enough current to > keep it rotating, but not enough for startup torque.
That was my thought and I checked, not the problem. I suspect that the magnets in the rotor have gotten really weak. Allison
