On Jun 26, 5:23*pm, Robert Macy wrote:
Anybody have a schematic for the fan driver circuitry for this item?

No matter what the switch is set at, the fan runs at medium speed, and
not well at that.

A schematic would let me know if voltages on the driver are correct,
or not.

Robert

Had to answer my own question here, since oddly, no answers came in
for this one.

Problem is now solved.

The fan's bearings slightly 'gummed' up with time. Then, no mtter
what the speed setting, the fan ran, but made a 'hum-like' noise and
ran at almost a single speed - too slow for fast, about right for
medium, and too fast for silent. Always making that AC mains based
tone. All very misleading observations that suggested the electronic
drive failed.

Solved problem by soaking the bearings at each end of the squirrel
cage fan [not very serviceable parts, but almost accessible] then the
fan was back to proper operation.

Lesson learned: Don't jump to conclusions. Mechanical almost always
fails first, then Electrical.

Robert