If the chip is burned out, it could be :
1) a motor seizure (blocked motor) - this could be easy to check , just move the drive in a half circle rapidly near the ear and you could hear the platters slightly moving (keep it tightly grip....

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2) short circuit in the windings of the motor
3) (most probably) an overvoltage on the +12V line due to spike or power supply failure. In this case, probably there's not only the L6262 broken.
I don't remember now if the L6262 drives the VCM too, but get it checked.
If the head latch is blocked, I think this could lead to failure of the driver (overload). Those motor/solenoid driver chips are short-circuit protected but can do nothing for overload and the thermal protection most of the times have no time to act...
If you have a MILLIOHMETER you can try measuring the resistance between common and the phase terminals of the suspect motor and a known good one. Don't use common multimeters because they can't appreciate fractions of ohm and have no compensation for the resistance of the cables. An ideal way to check windings and VCMs I think is an impedance meter because if there's a short in the middle this parameter varies significantly more than resistance.
Let me know...