Start unplugging/disconnecting stuff until you get down to psu,mobo,cpu+hsf.
If it still won't power on your down to 3 parts.
Move those 3 parts out of the case and on to a piece of cardboard.
If it still won't power up remove the cpu+hsf.
Asrock Z170 K4/D3
i5 7500
EVGA 450B PSU
GTX 1050 Ti
1x8 DDR3L 1600
I ran through troubleshooting guide and I can't figure out the problem. Everything in place, it has no beeps and no video at all.
Removing the RAM makes it do RAMless beep, so I'm thinking maybe it's the RAM? I've tried all RAM slots, replacing CMOS battery, power supply works with another motherboard, front headers connected properly, everything is brand new. I don't know what else to do.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic