How to use a multimeter to detect damaged LED Bead?
LED lighting bead usually adopts series and parallel connection. When LED lamp bead is damaged, the typical characteristic of fault is that the brightness is not enough. For damaged LED lamp beads in series and parallel lines, the following methods can usually be used to detect.
Judging whether it is good or bad:
(1) Multimeter detection and judgment method. Since the LED lamp bead has the characteristics of a diode, it can be detected or judged by using a digital multimeter diode block or a pointer type multimeter R×1 block in the road or the open circuit. If there is no problem with the LED lamp bead, the LED lamp bead will light up when detecting. If the detected LED lamp bead has no diode characteristics and will not emit a slight star illumination, it will be judged to be damaged.
(2) Parallel judgment method. For some aging LED lamp beads, the use of multimeter detection can often see the micro-star lighting, but still not enough brightness after power-on. In this regard, a parallel method can be used to find the aging LED lamp beads. Take a 3W bulb as an example. The specific method is as follows.
(3) LED parallel determination method. Using a well-functioning 1W LED, each pin is soldered with a short wire as the detection lamp, and then used to short-circuit each LED lamp bead in the bulb. Once it is shorted to an LED lamp bead, 3W The brightness of the bulb will increase greatly, and the LED bulb that is shorted is the aging LED lamp bead. After replacing the new one, the fault can be eliminated.
(4) Wire shorting method. If there is no such good LED at the moment, you can also use the short ends of a short wire to short-circuit each LED bulb in the bulb. Once it is shorted to a certain LED bulb, the brightness of the 3W bulb will increase greatly. The LED lamp bead that is shorted is the aging LED lamp bead. After replacing the new one, the fault can be eliminated. If there is no new accessory to change at a time, you can also short-circuit the aging LED lamp bead at both ends. Once you have purchased a new accessory, you should replace it in time.