- Mar 29, 2011
I tested the FMT, exactly the same results. I don't know if this helps, the driver emitted the distinct high frequency sound mentioned in the datasheet, although the input voltage is correct and the source is able to supply enough current. It emitted the same sound in buck and boost mode, also on 3 and 5 diodes.
if you can hear that sound it means the input power is dropping below the point in which it can sustain regulation.
pretty sure it's a input power supply problem