Question PC turns on then off

[FrannyPanny]

I changed the motherboard and power supply yesterday, because i diagnosed them as problems. Before the changes the PC wouldn't turn on, now with the changes it at least turns on but then turns off instantly. I'm thinking the RAM may be the problem. Any help?
Specs:

CPU: Intel Core i7-7700K 4.2 GHz Quad-Core Processor

CPU Cooler: CRYORIG H5 Universal 65 CFM CPU Cooler

Memory: Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-2400 Memory

Storage: Toshiba 2 TB 3.5" 7200RPM Internal Hard Drive

Video Card: EVGA GeForce GTX 1080 8 GB Superclocked Gaming ACX 3.0 Video Card

Case: NZXT S340 Elite ATX Mid Tower Case

Power Supply: be quiet! System Power 9 CM 700 W 80+ Bronze Certified Semi-modular ATX Power Supply

Operating System: Microsoft Windows 10 Home OEM 64-bit

Case Fan: Corsair Air Series SP120 High Performance Edition (2-Pack) 62.74 CFM 120 mm Fans

 

[sizzling]

What motherboard?

 

[FrannyPanny]

What motherboard?

Sorry forgot about that.

Mobo: ASUS Strix z270f gaming

 

[FrannyPanny]

I changed the motherboard and power supply yesterday, because i diagnosed them as problems. Before the changes, the PC wouldn't turn on, now with the changes it at least turns on but then turns off instantly. I'm thinking the RAM may be the problem because when I remove the RAM and start it up it still turns on and off. Any help?
Specs:

CPU: Intel Core i7-7700K 4.2 GHz Quad-Core Processor

Motherboard: ASUS Strix z270f Gaming

CPU Cooler: CRYORIG H5 Universal 65 CFM CPU Cooler

Memory: Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-2400 Memory

Storage: Toshiba 2 TB 3.5" 7200RPM Internal Hard Drive

Video Card: EVGA GeForce GTX 1080 8 GB Superclocked Gaming ACX 3.0 Video Card

Case: NZXT S340 Elite ATX Mid Tower Case

Power Supply: be quiet! System Power 9 CM 700 W 80+ Bronze Certified Semi-modular ATX Power Supply

Operating System: Microsoft Windows 10 Home OEM 64-bit

Case Fan: Corsair Air Series SP120 High Performance Edition (2-Pack) 62.74 CFM 120 mm Fans

 

[rocktalkrock]

Have you tried booting the motherboard outside the case?

 

[FrannyPanny]

Yep, same problem persists

 

[rocktalkrock]

Yep, same problem persists

What do the 4 small Q-LEDs on your motherboard (next to the 24-pin power connector) show when you boot?

The POST State LEDs provide the status of these key components during POST (Power-On Self-Test): CPU, memory modules, VGA card, and hard disk drives. If an error is found, the critical component’s LED stays lit up until the problem is solved.

 

[FrannyPanny]

What do the 4 small Q-LEDs on your motherboard (next to the 24-pin power connector) show when you boot?

The POST State LEDs provide the status of these key components during POST (Power-On Self-Test): CPU, memory modules, VGA card, and hard disk drives. If an error is found, the critical component’s LED stays lit up until the problem is solved.

None of the 4 LEDs light up, and the orange LED above the 24 pin connector lights up which according to the manual means that power is going through the motherboard and the components.

 

[rocktalkrock]

Try booting with no GPU, using the onboard graphics, no drives connected and just 1 stick of RAM in slot DIMM_A2 to see if you can get into the BIOS.

 

[FrannyPanny]

Try booting with no GPU, using the onboard graphics, no drives connected and just 1 stick of RAM in slot DIMM_A2 to see if you can get into the BIOS.

tried didn't work

 

[FrannyPanny]

Recently my PC broke and it wouldn't turn on at all. I recently changed my mobo and my PSU do due to them being faulty, and now my PC turns on then straight off. The Power LED is on, and none of the critical error LEDs are on, but I can't troubleshoot the problem. I tried using one Ram stick and switching DIMM slots and no RAM but the same problem persists. If a CPU is faulty will it turn on then off immediately? I think the problem is my RAM but I'm not 100% sure.

Specs:

CPU: Intel Core i7-7700K 4.2 GHz Quad-Core Processor

Motherboard: ASUS Strix z270f Gaming

CPU Cooler: CRYORIG H5 Universal 65 CFM CPU Cooler

Memory: Corsair Vengeance LPX 16 GB (2 x 8 GB) DDR4-2400 Memory

Storage: Toshiba 2 TB 3.5" 7200RPM Internal Hard Drive

Video Card: EVGA GeForce GTX 1080 8 GB Superclocked Gaming ACX 3.0 Video Card

Case: NZXT S340 Elite ATX Mid Tower Case

Power Supply: be quiet! System Power 9 CM 700 W 80+ Bronze Certified Semi-modular ATX Power Supply

Operating System: Microsoft Windows 10 Home OEM 64-bit

Case Fan: Corsair Air Series SP120 High Performance Edition (2-Pack) 62.74 CFM 120 mm Fans