Next time it happens, pull the platter off and see (smell) if the odor is more obvious, or even if there's some smoke. At the same time, look for any obvious signs of something awry on the pc board.
Unfortunately, you can't leave the platter 'on' while doing the inspection, since it will harm the motor (there's a warning sticker under the mat) but if you move fast you may be able to detect the cause (resistor frying, etc.).
Unfortunately, you can't leave the platter 'on' while doing the inspection, since it will harm the motor (there's a warning sticker under the mat) but if you move fast you may be able to detect the cause (resistor frying, etc.).