Shorted fan controller PLZ HELP

Shlouski

Shlouski

VIP Member
I was testing a working circuit when my hand slipped and i shorted one of the fan controllers. It controls 6 fan in one unit, the other 5 still work, but now one won't run a fan. I think i hit the capacitor when i slipped, then it sparked. Each individual controller has its own capacitor, i have tested them all with my multimeter (ohms) and all go to about 400k and the other on the fan that doesnt work about 85k, could this be the problem?
 
Did you test the capacitors with them still in situ? If so you measured the resistance of each capacitor and everything connected in parallel to it. You cannot measure resistance of a capacitor even when disconnected. Your meter measures resistance by putting a voltage from its battery across the component and measuring the current. Confucius he say R = V/I.

I haven't tried it for a long time but what should happen is that you get a charging current to begin with so it sees low resistance and when fully charged the current is zero so you see a high resistance. Could be the other way round! I suppose the fact the indicated resistance changing is a guide the capacitor is still working to some extent. Someone correct me if I have to re-do Basic Electronics 101.

The fact that the one circuit is different could be very significant (assuming all fans are off so the circuits are under identical load).
 
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from wat i just watched, the battery will charge the capacitor to a certain point, well im not sure of the measurements, but 5 charge to 400 and the 1 on the broken fan charges to 85. As it charges resistance goes up.
 
You are not being very specific about how you are testing.

Assumed that the unit is powered down. Confirm that if true.
Testing is meaningless if powered up and 5 of 6 fans are running. The non-running circuit is bound to be different.

Are all the capacitors still connected to their circuits?
If the capacitors are still connected, sure, one circuit is different, but is the capacitor faulty or another component of the circuit? You cannot tell without disconnecting at least one leg of the capacitor. I would have thought it more likely that any solid state components on the controller output would have been damaged. Are circuits fused? Model of controller? Website?
 
i swapped a capacitor over, then the one i put in would not charge properly, but when removed it was fine, so its something else. There is no noticeable damage or points fused on the circuit.
 
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