Thanks folks! The overall problem is that LED lights in my rangehood aren't working. I misdiagnosed it. The driver seems to be producing steady voltage. One of the LEDs is bad and since they are in series, both LEDs are off. I just need to buy a new LED.
Thanks Martaine2005! I am located in San Francisco Bay Area. I will buy their LED this time and then do a surgery on the old LED to prepare for the next time.