Asrock z270 extreme 4 red light plus no signal

Needsupport wrote: Subject says most of it dont know what to do

The subject says most of it... so where is the rest?

The red LED is the dual UEFI/BIOS indicator LED, main or backup selected, main by default. So that means nothing.

No signal to the monitor I assume? Is this your first PC build? So you get nothing on your monitor at all?

Let the questions begin:

What other hardware are you using?

DDR4 memory, capacity and full model number to check for compatibility.

Using a video card or Intel iGPU? If a video card, what model?

Processor being used?

PSU being used? Do you have both the 24 pin ATX cable and 4/8 pin CPU power cable connected? Both are essential, the board and CPU will not start unless both are connected to the board.

What SATA drives are being used? Are they connected to the Intel or ASMedia SATA ports?

Or are you using an M.2 SSD?

The more you tell us, the better the chance we can figure it out. All we can go on is what you tell us. We don't have your PC in front of us to look at and check for ourselves.