Today, I found my led light bulb not working and so I replaced it with a new one. Out of curiosity, I opened the damaged one to see what was inside. I saw a series of 16 leds. I have experience in checking the leds strips for using as backlight in tv. Therefore, I would like to do the same to check which led in the bulb is not working. Initially, I set my bench power supply to 3V and 200mA, and test each led. I found that I needed to raise the voltage to 7V so as to make the led to light up dimly. I found one led did not light up, and I think that one has been damaged. When I went to test the next led or the second next one, it was lighted up very brightly. I thought that one was shorted (but when I tested it with a multimeter, it is not shorted) and so I lowered the current of the power supply to 100mA and test again hoping that this will avoid damage to the power supply . I found that led was still lighted up very brightly. Then I further reduced the current of the power supply to 10mA and test again. I got the same result and the power supply is not working after that.
My power supply is Gophert CPS-6005. The maximum output voltage is 60V and maximum current is 5A. It should have over voltage and over current protections according to the manual. Was I not using it properly and so it was damaged? Or was it the power supply problem (not providing current protection)?
Now the power supply output voltage is 0.08V. The setting can change the voltage but after that it will return back to 0.08V. Visually, I cannot see any damaged component. The fuse is also normal. Which component will probably be damaged if I want to fix the power supply?
My power supply is Gophert CPS-6005. The maximum output voltage is 60V and maximum current is 5A. It should have over voltage and over current protections according to the manual. Was I not using it properly and so it was damaged? Or was it the power supply problem (not providing current protection)?
Now the power supply output voltage is 0.08V. The setting can change the voltage but after that it will return back to 0.08V. Visually, I cannot see any damaged component. The fuse is also normal. Which component will probably be damaged if I want to fix the power supply?
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