PSU won't boot the motherboard!!!?

Greetings. I am currently using a Corsair RM650x modular power supply. When I connect it to my Gigabyte GA-series motherboard, the board receives power, yet it refuses to actually boot up. The motherboard is brand new. Interestingly, I have already tested this power supply on several other boards and it powered them all without issue, so I cannot fathom why it fails here. Everything is connected correctly; I simply don't understand the problem. I would appreciate some assistance. Thank you in advance!! 😵🤦

Since you’ve already ruled out the power supply, it’s pretty much gotta be a motherboard issue at this point. Did you plug in both the 20 or 24-pin connector to the board?
Did you hook up the 4/8-pin CPU power cable?
And just to double-check—is the case power button connected to the motherboard pins correctly?

Maybe try jumping the motherboard manually—just connect the power supply and the processor and see if it'll boot then.

It’s possible you're dealing with a different faulty component entirely. Try unplugging everything—your hard drive, all USB peripherals, and so on—then attempt to boot it up again.

The motherboard is asking for a 24-pin power connection, while the CPU requires a 4-pin. I’ve double-checked the front panel connectors to ensure they're seated correctly... I even tried running just the processor by itself, but still nothing. The green LED on the board lights up, but that's it.😵
Everything else in the build is in perfect shape. I've been troubleshooting by stripping it down and testing components one by one, but the result remains the same.

Where can I find a new s775 motherboard? Does it look decent visually? Make sure there aren't any bloated capacitors, leakage, or obvious damage. Try resetting the BIOS—either with a jumper or, even better, just pull the battery out for about half an hour...

Also, try flipping the polarity on the wires going to the power switch connector on the board.

darkowl72 said:Where are you even going to find a new s775 motherboard these days? Is it in decent shape visually? Check for any bulging capacitors, leakage, or obvious physical damage. Try resetting the BIOS—use the jumper, or better yet, pull the battery out for about half an hour...

Also, try reversing the polarity on the wires going to the power switch connector on the board.

My cousin used to pick this stuff up all the time back in the day... he was actually the first one to unbox it. haha. Visually, everything looks fine; there isn't any damage at all. I'll give those suggestions a shot. 👍

It’s possible the battery kicked the bucket too...

darkowl72 said:The battery might be dead too...

What does the CMOS battery have to do with getting it to boot?

That was just a comment regarding the battery state on such an ancient motherboard. I never said the battery had anything to do with the system booting up; it’s about saving BIOS settings, which I assume you already know...

http://www.asus.com/Motherboards/P5ND/HelpDesk_CPU/
Here is the list of compatible processors for this board. My advice would be to install one of the CPUs supported by the initial 0107 BIOS version first, then check if it boots up.

I managed to get the board running using an MS power supply, so the battery seems fine—I don't think there's any connection there. The board is currently running this Intel Core i7 (3.00GHz,1333FSB,L2:4MB,rev.G0) and, naturally, the board supports it perfectly.😵
Is it possible that certain BIOS settings are preventing it from booting up?

Maybe pop the power supply open and check if the capacitors look blown. Also, I guess you could try mashing the power button a few more times to see if it finally kicks in

The capacitors look perfectly fine... I've given it a shot, but no luck.
Is there any chance some BIOS settings are preventing the boot process?😁🙂

Try testing that processor on another 775 motherboard just to be 100% certain the issue isn't with the CPU itself.

There aren't any settings in the BIOS to toggle one power supply on while keeping the other off.
From what I can gather based on your posts, you managed to get the motherboard running using the MS unit—so it seems pretty clear the issue lies with this Corsair

The processor has been tested and is fully functional. I managed to boot up two other Gigabyte GA-series motherboards using this Corsair RM650x without a single hiccup.🥱🙂

I wish I could give you a straight answer as to why that Corsair power supply isn't playing nice with that Intel motherboard—but honestly, I can only guess, especially since you mentioned they work fine in other setups.

Edit: the only other thing I can think of is grabbing a multimeter to check the 24-pin connector... just to see if all the voltages actually match what they're supposed to be.
http://www.smpspowersupply.com/connectors-pinouts.html

Did you happen to use the same RAM sticks on that other Intel motherboard? It strikes me that this "new" board might just be struggling to handle the specific memory you're throwing at it—it’s a common enough headache.

I used the exact same RAM sticks on her build... could that actually be an issue? Because if there's no RAM detected at all, even the fans might start spinning up like crazy.😛🥱

It’s absolutely possible. If there’s no RAM, there’s no work being done at all.