Question New build PC. Won't boot. CPU and case fans work but black screen only. Any guru know why?

[Kolakube]

Ive built the following system. There are more bits but I un-built it to make things as simple as possible to help fault finding.

Mobo - Asrock B660M-HDV
CPU - i5-12400F
RAM - Ripjaws DDR4 3600 8GB x2
PSU - Corsair CX750

I am using the Mobo's HDMI out directly to my monitor. The monitor cables works on my PS4. Also I have tried my Media PC's HDMI cable what works fine on my Media PC, so its not that. My Monitor works on my media PC so it isnt that either and as said tried with two HDMIs.

Before I realized I had this issue I have a proper GFX card. Blank screen. Hence me stripping right back,

I have even unplugged from the motherboard the Audio, USB and other such things. Only thin plugged in are the power and reset buttons and the fans.

Only reason I know this is semi working is the case and CPU fans move when the on button is pressed

Any help apreciated

 

[Lutfij]

Mobo - Asrock B660M-HDV
CPU - i5-12400F
RAM - Ripjaws DDR4 3600 8GB x2
PSU - Corsair CX750
Which CX are we looking at here? The green labelled unit or the grey labelled unit? If the unit is being recycled from an older build, how old is the PSU and what did it power prior to today?

I am using the Mobo's HDMI out directly to my monitor.
Your motherboard has display output ports but your processor lacks an iGPU as it's an F SKU processor so no matter what you do, you won't get a display out from the system. You're going to need a discrete GPU.

Before I realized I had this issue I have a proper GFX card.
Which would be?

Try with one stick of ram on slot A2. Check to see if there are any bent or broken pins on the motherboard's CPU socket.

Moved thread from Motherboards section to Systems section.

 

[Kolakube]

Hiya, Thanks for swift reply.

CX750 bought second hand here. https://www.ebay.co.uk/itm/396095704097
No idea to its history sorry. Seller does claim to have tested and had 1500 positive feedback's.

Right thanks re GPU. I can put my card back in. Its an XFX Quicksilver 319 RE 7800 GT. If this makes any diff. I had originally had my whole PC built so it was the same black screen with my GPU installed. Anyhow, Ill re insert it.
I didn't know that about CPUs and Mobo GFX ports. Thank you.

Will do re RAM in A2.

CPU fitted like a a kids jigsaw. Just slotted right in. I can check this of course if need be. Ill do this last thought.

Ive built many PCs over the decades. Only as a hobby for self and friends. Im no expert but never had power on and a black screen. Always got something on the screen.

Thank you very much for the reply. I'll go do, then come back and double post below to keep reply and info separate.

Kindest regards

 

[Kolakube]

ADDITIONAL

Ok, RAM went in B1 (No A2 just to be specific) So running on 8 gig stick in only B1. A1 now empty.

Reinserted GFX card. Plugged power into it from PSU checked and correct.

Got an HDMI cable going to my TV.

Got a Display port cable going to a different PC monitor. (GFX has 4 outs. 3 x DP and 1 x HDMI.)

Booted PC and exact same. Blank screen.

I haven't / am reluctant to re try the CPU

 

[Kolakube]

Got it. CPU wasent connected properly from PSU to Mobo.

See this superb guide to anyone else who gets stuck

"No POST", "system won't boot", and "no video output" troubleshooting checklist

"No POST", "system won't boot", and "no video output" troubleshooting checklist This checklist is a compilation of troubleshooting ideas from many forum members. It's very important to actually perform every step in the checklist if you want to effectively troubleshoot your problem. 1.Did you...

forums.tomshardware.com

 

[Lutfij]

Hiya, Thanks for swift reply.

CX750 bought second hand here. https://www.ebay.co.uk/itm/396095704097
No idea to its history sorry. Seller does claim to have tested and had 1500 positive feedback's.

Right thanks re GPU. I can put my card back in. Its an XFX Quicksilver 319 RE 7800 GT. If this makes any diff. I had originally had my whole PC built so it was the same black screen with my GPU installed. Anyhow, Ill re insert it.
I didn't know that about CPUs and Mobo GFX ports. Thank you.

Will do re RAM in A2.

CPU fitted like a a kids jigsaw. Just slotted right in. I can check this of course if need be. Ill do this last thought.

Ive built many PCs over the decades. Only as a hobby for self and friends. Im no expert but never had power on and a black screen. Always got something on the screen.

Thank you very much for the reply. I'll go do, then come back and double post below to keep reply and info separate.

Kindest regards

That's the green labelled unit. That unit is considered a disaster within the industry. To add, you picked it up secondhand. You're looking for an excuse to ruin all of your investments. I would replace that unit, ASAP with something reliably built.