Dualshock 4 Blinking light blue and not working

I like repairing electronics and a friend of mine gave me a DS4 CUH-ZCT2 JDM-055 (7th gen with the lighting touch pad) controller. When I press the PS button, it used to blink red but now it doesn't (probably battery is low) but when I connect it via USB to a power source it blinks light blue, connects to my pc (I don't have a PS4) for a couple of seconds and then disconnects. I measured the usb board with a multimeter and the port works fine but I am suspecting that the mainboard doesn’t work properly. Can someone provide me with a diagram of either the JDM-055 mainboard or the ext connector on the bottom? I'll be eternally thankful.