I tried to power my Raspberry Pi via the GPIO header, but it didn't work. I powered it with exactly 5v, but it won't boot, but the Status LED "ACT" is on. It's darker then normal, but it's on. I think the Raspberry is OK, because if I power it via USB, everything's fine.I wonder about that, because I read it's directly connected to the 5v Logic, so it must be connected to the Micro-USB. But if this was the case, it would work, would't it?
By the way: I double-checked the connections to the Pins, they're OK.