Ceramic capacitor in air conditioner DPAC12010H

Hi there, 

I received a not-working air conditioner model DPAC12010H from someone who didn't need it anymore, and I took it to a friend who works with refrigerators to see if we could find the problem.

We took it apart, and we found that a fuse mounted on the main PCB was shot. The fuse is 120V and 3.75A so I suppose it's only for the control circuit as the whole air conditioner runs at more than 9A on max capacity.

Anyway, we temporarily bypassed the fuse with a copper wire to continue testing. We plugged it in, and immediately a component on the PCB (which I now believe is a ceramic capacitor) spew sparks and melted it's insulation. However after this incident the air conditioner works perfectly, and it blows very cool air (its a 12000 BTU machine after all).

However I'm still concerned about that capacitor. I can not post a picture right now, maybe when I get back from work. It was brownish yellow, about 3/4" in diameter roughly same shape as a nickel. Does anyone have any idea what that capacitor might be for? Since the air conditioner is working now I'm guessing the sparks made it conductive, or maybe it's used for the dehumidifier which I have not tested. 

I will buy a new fuse today and see what happens.

The air conditioner draws about 9 A at full operation.

Any help would be greatly appreciated.

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caitlinsdad4 years ago
Capacitor has functions as part of the power supply itself or the motor http://en.wikipedia.org/wiki/Motor_capacitor
colorex (author)  caitlinsdad4 years ago
Maybe it regulates some transformed voltage... However there are three relays, of which two are for fans and one is for the compressor, and I've found (in the air conditioner) two of the larger box type capacitors like the ones found in refrigerators. I doubt a small PCB capacitor would provide enough oomph for a big fan...
It may be part of the control circuit for the thermal sensors/feedback/speed etc. Post a pic or look up the service manual for the unit. Good luck.
colorex (author)  caitlinsdad4 years ago
It might be this, as Goodhart suggested. Will post a picture as soon as possible. I tried to find the circuit diagram but cant find it anywhere.
Of course he didn’t need it any more it don’t work.

Do you get a buzz on your radio when the air conditioner is running and no buzz when it is not running? If that is the case the capacitor is to stop the buzz in the radio.
colorex (author)  Josehf Murchison4 years ago
Will try. I understand what you mean as I read a lot about video systems running on an RC airplane where the motor causes electrical noise in the video feed.
Goodhart4 years ago
are you SURE it's a capacitor? Sounds like it may be a thermistor or something, and if it is burnt/shorted, you'd get the same "show".
colorex (author)  Goodhart4 years ago
It's possible. I only identified this component as a capacitor by searching online for "electronic component identification". However the component was just plain mounted on the PCB, no extension going to anything...