Can I Test My Motherboard with a CPU That Has a Bent Pin?

You might want to be cautious. Typically, a CPU with a bent pin won't work properly. If you really want to try, you could look up the pin map for your specific CPU. If the bent pin is related to grounding, testing it might be fine. Alternatively, if you're steady enough, you could try to carefully straighten the bent pin with some small tweezers or a clip.

What CPU and motherboard are you working with? If it's the Ryzen 7 2700x on a Gigabyte B550 UD AC, I’d suggest not using the CPU with the bent pin, especially since your PC turned on briefly and then flickered out. That doesn’t sound good.

It's generally not a good idea to try seating a CPU with a bent pin. It won’t sit flush and could end up damaging more pins when you try to clamp it down. You could attempt to straighten it if you have a steady hand, but be very careful!