My Raspberry Pi5 8gb got halfway through the first boot, shut down, and won’t attempt to boot. it’s got a solid red light, and in a few seconds the PMIC gets hot enough to burn you. I have contacted Sparkfun support, and the said they won’t do anything and I need to ask here for help replacing the PMIC which might not be available. So I’m asking here, but I’m sure the answer will be it can’t be fixed.
I’ve always noticed that when a new version of the pi comes out, there are a lot of failures. Kind of like it takes them a while to really nail down getting production correct.
Sparkfun has a returns page, you might try filling ot a return request there and see if that’s faster.