I'm trying to identify the SMD component (marked as D7 with an underline) on a circuit board of an ARGB LED controller. I think it is a diode or resistor, but I'm not sure about it. Please can I get some help with identifying it?
That looks like an LP-USML400 resettable "polyfuse" made by Way-On.
D7 with mark F2, It's a Fast tripping resettable circuit protection.
Looks like it could be a fuse. Looks identical to the one to the 12V pin from this.