Hi guys! I took this accessory apart to try to get it working. I found a pcb and a DC motor. Jumped the motor with DC - works. The board does not work (ac to DC) How do I test the components on the board to replace the bad one? No burn marks seen. 2 caps,linear voltage reg and a bridge rectifier. thanks, Art
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Disconnect the board from the motor. Attach the AC and power it up. Read the + and minus voltage on the round rectifier. Should be about the same voltage of the AC input, just DC. Then measure pin 2 against 3 on the Voltage regulator with a heatsink. Depending on its rating it should be about 5 or 6 VDC.
I would guess a bad regulator if the rectifier works and all the board traces and solder joints are good.
Sometimes a motor can be bad (draw too much current) will work on a battery or at high voltage, but won't work on the small regulator. G
Put board under power. Put meter across the bridge DC terminals. It should read a DC voltage. 41% higher than the AC input. If it does not, and reads only the input voltage replace the 2 caps first. If it still does not read right replace the bridge.
If the voltage mentioned reads correctly measure the voltage on the regulator output. (terminals 2 and 3 on a 78xx series regulator) It should read whatever volts DC. If it is a 7809 it should read 9 volts for example. If it does not replace the regulator.
here is a pic of a 78 series regulator a electrolytic capacitor is likely across the bridge + and - not shown.
Most likely bad components are the regulator followed by the electrolytic caps.
Dale H
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