Question Upgraded old system with NEW CPU, greenlight but no IO

[afe]

Old CPU(Still working): i3-4130
New CPU(Boots, motherboard green light but no Video display, USBs e.t.c.): i7-4790k
Motherboard: H871-PLUS
I successfully updated the bios to the latest version (2003 from https://www.asus.com/in/supportonly/h87iplus/helpdesk_bios/)

Is there a compatibility or power issue I maybe missed or could the CPU I bought be faulty?
The fact the motherboard system shows a green light I assume indicating no issues makes it a weird issue to me.

When I start the pc with the new CPU the fans spin, light goes green like the original system but none of the usbs delivery power and there is no display. I tried to plug a keyboard or mouse but it doesn't light up.

Would appreciate any ideas.

 

[Lutfij]

Welcome to the forums, newcomer!

I successfully updated the bios to the latest version (2003)
Did you clear the CMOS after verifying your BIOS was flashed tot he latest version? You're advised to disconnect from the wall and display, then remove the CMOS battery, then press and hold down the power button for 30secs to drain any residual power. Replace the CMOS battery after 30mins.

Is there a compatibility or power issue I maybe missed or could the CPU I bought be faulty?
You're specs are incomplete. When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:
include the age of the PSU apart from it's make and model.

As for your motherboard, have you inspected the CPU's socket for any bent or broken pins?