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Can a motherboard turn on without a cpu?

Go to solution Solved by SpookyCitrus,
5 hours ago, TranquilElder said:

That seems to be the case here :/

Most of the time with components like motherboards in order to get into the bios a CPU has to be installed most will not power on at all while some will power on for literally a split second and it's not even enough to spin the system fans. As Bishop said outside of the Enterprise market very few boards turn on without a CPU installed and B450 is a chipset that doesn't. I think some of the ASUS high end boards do but that's for updating bios before you install the CPU like CUDA said in his post.

I'm trying to run power trough a motherboard to check if my fans are working

I have everything plugged in to the motherboard except the CPU, so my question is can a motherboard turn on without the CPU? 

Does the CPU have to be in a socket for a Motherboardto turn on?

I can’t  short the Fpanel because it doesn't do anything when i put my screwdriver in there and I’ve tested my PSU with the paperclip method so trying to figure out if my motherboard is dead or i just need a CPU to turn it on.

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Usually they don't turn on at all without a CPU in the socket. 

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Yes it turns on without the CPU and you can see the fan spin or not.

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It really depends on your motherboard.
BIOS can run and even output to a display without a CPU, but there are almost no implementations of this outside of the enterprise market.

 

For the desktop market it really is a mixed bag, you may get a constant beep warning that you have no CPU.  Or you may get the system briefly power on, then off again.  Or something in between.

 

What I can say for certain though, you will not damage any component by powering it on without a CPU.

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5 hours ago, CUDAcores89 said:

Only once have I had a motherboard turn on without the CPU installed, and that was because it was an asus board which could update it's BIOS without a CPU/RAM installed. 

 

Other than that, I am not familiar with any motherboard that will turn on without a CPU installed since the CPU generally shorts many important functions of the motherboard together to allow the system to turn on.

I have a gigabyte b450m ds3h and my ryzen is about to arrive.

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2 hours ago, Bishop Crane said:

It really depends on your motherboard.
BIOS can run and even output to a display without a CPU, but there are almost no implementations of this outside of the enterprise market.

 

For the desktop market it really is a mixed bag, you may get a constant beep warning that you have no CPU.  Or you may get the system briefly power on, then off again.  Or something in between.

 

What I can say for certain though, you will not damage any component by powering it on without a CPU.

I don’t nt think mine can turn on without the cpu (gigabyte b450m )

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6 hours ago, SpookyCitrus said:

Usually they don't turn on at all without a CPU in the socket. 

That seems to be the case here :/

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5 hours ago, TranquilElder said:

That seems to be the case here :/

Most of the time with components like motherboards in order to get into the bios a CPU has to be installed most will not power on at all while some will power on for literally a split second and it's not even enough to spin the system fans. As Bishop said outside of the Enterprise market very few boards turn on without a CPU installed and B450 is a chipset that doesn't. I think some of the ASUS high end boards do but that's for updating bios before you install the CPU like CUDA said in his post.

Main Desktop: CPU - i9-14900k | Mobo - Gigabyte Z690 Aorus Elite AX DDR4 | GPU - ASUS TUF Gaming OC RTX 4090 RAM - Corsair Vengeance Pro RGB 64GB 3600mhz | AIO - H150i Pro XT | PSU - Corsair RM1000X | Case - Phanteks P500A Digital - White | Storage - Samsung 970 Pro M.2 NVME SSD 512GB / Sabrent Rocket 1TB Nvme / Samsung 860 Evo Pro 500GB / Samsung 970 EVO Plus 2tb Nvme / Samsung 870 QVO 4TB  |

 

TV Streaming PC: Intel Nuc CPU - i7 8th Gen | RAM - 16GB DDR4 2666mhz | Storage - 256GB WD Black M.2 NVME SSD |

 

Phone: Samsung Galaxy Z Fold 4 - Phantom Black 512GB |

 

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My B450m DS3h didn't turn on with a CPU or RAM installed.

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  • 1 year later...

I have a strix b550-f wifi and an evga 750 b5 psu. I wanted to know the same thing, becouse new build, and this is what happened. I have my ram installed 24 pin atx connected, m.2 SSD connected, ll120 fans connected with the lighting node core plugged in, front panel audio, USB 3.0,  power LEDs power and reset switch. The only thing that turned on was the rgb Asus logo on the motherboard and all of my USB sockets seemed to have power as I could charge my phone on all of them front and back, now that I think about it my board does have an option to update bios wo CPU with USB in the back. Which makes sense as to why only the USB sockets have power . My psu fan dint even turn on like it does with the power on self tester evga gives you. I tried every combination and nothing. Maybe the CPU completes some circuits or something idk. Also wanted to see my ram rgb and ll120 fans turn on, but I will have to wait for CPU and GPU.

IMG_20200731_152743052.jpg

 

 

IMG_20200731_152544329_BURST000_COVER_TOP.jpg

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  • 3 months later...
On 8/1/2020 at 8:00 PM, Liquidcooled69 said:

I have a strix b550-f wifi and an evga 750 b5 psu. I wanted to know the same thing, becouse new build, and this is what happened. I have my ram installed 24 pin atx connected, m.2 SSD connected, ll120 fans connected with the lighting node core plugged in, front panel audio, USB 3.0,  power LEDs power and reset switch. The only thing that turned on was the rgb Asus logo on the motherboard and all of my USB sockets seemed to have power as I could charge my phone on all of them front and back, now that I think about it my board does have an option to update bios wo CPU with USB in the back. Which makes sense as to why only the USB sockets have power . My psu fan dint even turn on like it does with the power on self tester evga gives you. I tried every combination and nothing. Maybe the CPU completes some circuits or something idk. Also wanted to see my ram rgb and ll120 fans turn on, but I will have to wait for CPU and GPU.

IMG_20200731_152743052.jpg

 

 

IMG_20200731_152544329_BURST000_COVER_TOP.jpg

Hey mate what ever eventuated from this, was it just the cpu not being installed that caused this or was their other issues 

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  • 2 weeks later...
On 8/1/2020 at 3:00 AM, Liquidcooled69 said:

I have a strix b550-f wifi and an evga 750 b5 psu. I wanted to know the same thing, becouse new build, and this is what happened. I have my ram installed 24 pin atx connected, m.2 SSD connected, ll120 fans connected with the lighting node core plugged in, front panel audio, USB 3.0,  power LEDs power and reset switch. The only thing that turned on was the rgb Asus logo on the motherboard and all of my USB sockets seemed to have power as I could charge my phone on all of them front and back, now that I think about it my board does have an option to update bios wo CPU with USB in the back. Which makes sense as to why only the USB sockets have power . My psu fan dint even turn on like it does with the power on self tester evga gives you. I tried every combination and nothing. Maybe the CPU completes some circuits or something idk. Also wanted to see my ram rgb and ll120 fans turn on, but I will have to wait for CPU and GPU.

IMG_20200731_152743052.jpg

 

 

IMG_20200731_152544329_BURST000_COVER_TOP.jpg

Yo dude i have the exact same problem did you ever fix it and how?

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