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The LED lights on our kitchen range hood have flickered out and I'm trying to order replacements, but not from the manufacturer, who unfortunately have none in stock and are waiting for a shipment of parts from overseas. No telling how long that may take at present. The LED lights, when turned on, are very faintly lit and there's a high-pitched whining buzz, like a mosquito near your ear, so I am also going to replace the LED driver. Under the present circumstances, technicians at the company are not available to answer questions and the customer service rep who is answering the phone and responding to emails knows even less than I do about LEDs.

With the multimeter set to AC (~), and the Range set to no fractional decimal positions, and the display reading 0000, I put the leads on the motherboard's two prongs where the black and white wires from the LED driver attach to it.

The reading is 121.

I switch the multimeter to DC mode (---), and test again, and the reading is 0000.

If I understand correctly, the LED driver should be one with full AC line input and of the "constant current" variety. But how to determine the output requirements for the driver?

There are two (2) LED lights, each with this spec: 

Max power: 1.5W and Input: <= 12V, Frequency: 50-60Hz.

Would a driver with the following specs be sufficient to run those two LED lights? 

Input Voltage (VAC) 100 ~ 204VAC
Input Frequency (Hz)    50/60 Hz
Output Voltage (VDC)    4 ~ 12 VDC
Output Current (Constant)   350mA
Output Power (W)    1 ~ 3 W
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    Since you've gotten this far into the hood, can you dig a little further to see if there's any technical info printed on the LED driver box? There's sure to be something in there since the hood mfgr most likely gets these wholesale from an LED supplier and doesn't custom manufacture the drivers themselves. – FreeMan Jun 12 '20 at 13:15
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    Please pull off the driver, search it for any marking or labeling, and shoot us good readable pix of same. – Harper - Reinstate Monica Jun 12 '20 at 13:25
  • The label on the driver was greasy and it was impossible to read the little numbers. Alll that was legible was the word DRIVER. When I wiped away the grease, the ink came along with it. The sticker is now perfectly blank. – mr blint Jun 12 '20 at 14:07
  • Are the two LED lights wired in series, or parallel? – Harper - Reinstate Monica Jun 14 '20 at 2:17
  • @Harper-ReinstateMonica: Judging from this diagram (pinterest.com/pin/519532507014287181 ) I'm not sure, since my wiring resembles neither. A black/white wire pair coming out of the driver connects to a plastic clip that feeds one light, and that same plastic clip has a second b/w pair emerging from its base, and that pair goes over to the other light. – mr blint Jun 16 '20 at 11:28
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Using the information you provided, each LED needs 125mA so the two of them would require 250mA. This value is below the rated output of 350mA of the driver you're referring to so it would overload the LEDs and burn them out faster. Look for one that's 250mA constant current.

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  • I do not understand how to calculate the mA needs based on the LED light's power and input. – mr blint Jun 12 '20 at 14:12
  • @mrblint 1.5 watt bulb divided by 12v = .125A X 1000 = 125mA times two bulbs = 250 mA – JACK Jun 12 '20 at 14:37
  • You've overlooked that the new driver is constant current. It's going to push 350mA whether the load wants it or not (within its voltage range). With the given 250mA load, the LEDs are going to be receiving 40% more current than they're designed for. – nobody Jun 13 '20 at 14:04
  • @nobody Good catch. I was thinking continuous ... just replaced a motor and needed continuous duty... had it on my mind. – JACK Jun 13 '20 at 14:50

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