How to save two Mitsubishi M2896 drive (spindle motor smoked!)

[Brent Hilpert]

On 2015-Mar-20, at 12:26 PM, Enrico Lazzerini wrote:
> IT WORKS!!! IT WORKS!!! AGAIN!!!!!
> Thanks BRENT!!!! Thanks for the schematics.
> 
> Well the problem were 3 solders. After to insert the D102 zener (maybe
> 12,5V) and the resistor R112 (180ohm) on their position it I set the 3rd
> wire to the ground, the pin7 of c358c change its level. I reconnect also the
> transistor Q101. The spindle motor do not want to work.
> I remember that pin 1,2 and 3 were soldered even on the component side of
> the PCB so I would wanted to try to solder them again: the spindle motor
> begun to rotate. What emotion!!!!
> 
> I not know if it rotate at the correct speed cause I have to rebuild on a
> table my old pc an to connect the 8" drive to see if with IMD software I
> will can to read a 8" floppy disk correctly, but at this moment the spindle
> motor works again!!

Great; if the 3rd-pin motor control does work then the 358 is likely OK and the speed regulation (that uses the other half of the 358) is likely good as well.