Before testing, the motherboard must be powered off and then discharged. Testing cannot be carried out while the power is on. The pin marked on the device corresponds to pin 1 of the optocoupler, and it from top to bottom. After many hardware updates and parameter modifications, the current generation is very easy to use. As long as the indicator light flashes, it must be good. Since there are many kinds of peripheral circuits of optocouplers, if it is always on or off, remove the light If you test the coupling again, you can 100% judge whether it is good or bad. It uses a type-c interface, which is rechargeable and the pins can be replaced. If the optocoupler pins are rusty or have glue, you can clean them a little in advance., Weight: 0.02425084882 pounds, Manufacturer: Malloy