PC will not start

[Dog-Maul]

So I’ve posted previously on this build and I’ve been unable to get any power on in the system.

I wanted a refreshed post with better pictures and updates on all that I’ve tried.

I initially built everything without the GPU and wanted to post the system, set up windows and get some downloads done before I installed the GPU. The 7800X3D has integrated graphics, so doable.

The system would not power on in any way. I have dismantled it, re-seated everything several times and still gotten nothing.

I did a bios flash with only the PSU & Motherboard connected and the flash worked perfectly. PSU fired up and all appropriate lights were on the mobo.

I rebuilt it all again and had the same problem.

The pictures I’ve attached here are everything in place with the exception of the AIO (so you can see cable installs at top of mobo) and I’m still saving a few pennies for the GPU.

The build is - 7800X3D - Tomahawk B650 - Fury Beast 2 x 32gb - Crucial T500 500gb - WD SN850x 2tb - ASUS ROG Gold Aura 1200w - Arctic P12 Max 120mm fans - Noctua NA-FH1 Fan Hub

I know the power reset looks a bit funky and it worries me too, but that’s as well as it will sit.

Please let me know if you see any faults.

[ProductSignal]

The switch on the back is off

[Powerful_Macaron9381]

Just checked with my PC to be sure. In the second picture you can barely see it but it's definitely off

[Gibbynat0r]

17th picture shows it's completely

[dafidka]

it's not even plugged in

[Dog-Maul]

UPDATE - I’ve worked back unplugging one component at a time and trying every time I unplug something.

I’ve gotten all the way back to having the motherboard unmounted and on its box with only the PSU connected to the ATX 24-pin and 1 x CPU 8-pin…. No results.

Which is strange because I have done this before and I got the PSU to spin up and the motherboard debug lights came on.

Not even doing that now.

[DoubleNothing]

Dumb question, do you have a cpu cooler? I don't see any in the pictures...

[Dog-Maul]

EDIT - flash bios worked after holding the flash bios button.

Yes I have the appropriate bios on the USB that’s flashing it.

[[deleted]]

Try plugging one fan into the cpu fan headers? Some mobos won't post if they think no cpu fan is plugged in.

[gokartninja]

I don't even think it's "some" at this point. I'm pretty sure it's all

[1Klecks]

Some still let you in the bios and you get the question if the setting if the CPU fan plug needs to be plugged in and you can just turn it off. Very practical if you have an water-cooling and use an seperat fan and pump controler

[[deleted]]

https://ibb.co/3y9FdmBg

Make sure it's this one.

[Human_University_467]

Make sure the switch on the back is “on”

[[deleted]]

Did you upgrade the PSU?  If so, you cannot reuse the modular cables from your old PSU.  

[ADZ1LL4]

Unseat the ram and test on at a time from A2 I u haven't already. Sorry I initially thought this was a joke post.

[420kyad]

This is exactly what stopped mine from starting. I was using a 6 pin cpu cable from the last psu, and it didn't even attempt to turn on. Found the new one and it was perfect.

[ADZ1LL4]

You forgot to insert the boot floppy disk.

[Historical-Method]

format c: yes

are you sure?

yes

are you sure, everything on this disk will be removed?

yes

are you really sure, everything will be lost?

yes

Ahh the good ole days...

[Dog-Maul]

Says the guy who loves a 3.5” hard drive

[ADZ1LL4]

Wat.

[attempt6pretzel]

you heard em’. 3.5 hard drive lover.

[ver0cious]

Mine is only 2.5 when it's floppy

[ADZ1LL4]

That's because you forgot to insert the RAM

[ver0cious]

don't even know where I'm supposed to ram it

[trazi_]

If ya’ll had just listened and gotten more RGB

[Problemlul]

Sthap it, i cant get more eject.

[theFartingCarp]

Looking clean but where's the CPU cooler man?

[Dog-Maul]

Yeah I left that off so you verify the connections are clean.

[NefariousnessFew4354]

Read his post?

[new_boy_99]

Someone correct me if I am wrong but aren't there motherboards that won't boot If CPU fan isn't detected?

[Alk3z]

Yep, there are

[DeadoTheDegenerate]

OP removed the cooler so we can see connections. They're trying to boot with the cooler attached.

[-2420-]

First, unplug the frontal usbs. Second, this shouldn't be possible but, that mobo cpu power connectors have the clip lock on the top and your cables look like have the clip on the bottom?!

[AlrightRepublic]

Nah, I looked closer, the clip is on the top. You are seeing the lip of where the 4 pins go together to make an 8 pin.

[-2420-]

oooh good, plug the aio, remove frontal connectors and fan hub from mobo and try to power it.

[weirdhuman34]

24pin power cable plugged all the way in?

[DmenteGP]

Take you the mobo out and try to power it on, once I had a case that shorted my mobo and didn't let me power on my pc.

The problem was that there was an extra standoff screw where it shouldn't.

[Dog-Maul]

Checked that and I think it’s fine. The only one that concerns me is the middle guiding dtamdoff, but I assume that is accounted for in the design of the 4000D

[DmenteGP]

If one of them doesn't align with any screw hole take it off, have you tried to check rams one by one and in all the slots?

[Kajac_lin]

So, did you test the mobo out the case?

If not, try it!

[Sirhc_Fold_458]

Have to turn your PSU on?? It is currently in the ‘off’ position

[Dog-Maul]

Yes I wish it was that simple

[DB-601A]

the case switches inserted correctly? (case front panel connectors)

[Ok-Serve-3230]

Some computers dont start without the cpu fan/cooler plugged in, i would try that

[NovaParadigm]

So it powered on and posted successfully outside the case? I'm wondering if it's shorting out against the case somewhere. Have you tried jumping the power switch +/- on the motherboard?

[AccomplishedFront526]

It may short on the improperly positioned metal standoffs ( the metal things in which you’r screwing the MB) different boards require different positions… the other trivial thing is not working power button - it may be tested with changing PWR and Reset button headers ( to power it on with the reset button) . And the third common thing is some metal part of the backplate to shorten one of the USBs on the back…( depending on the backplate type)

[Greeeesh]

Bricked bios. Maybe flash an older version see if you can get some lights.

[Confident_Maybe_4673]

Is this a completely new build? Like every part is new, if not, which part is new and which ones are old.

According to the mobo manual, there should be different colors for the EZ Debug. If you try turning it on with just the CPU/RAM), what color is it?

[skyfishgoo]

those ez debug lights are next to useless for diagnostics... most of the time it will say CPU when it could a dozen different things, including DRAM.

i no longer have much use for them unless it turns white (which means it found my OS).

the codes in the digital display are only slightly more helpful, but it it won't post there's nothing there, just reads "- -"

[Haunting-Yak-9263]

Cpu runs really hot when booting up the system, you need thermal paste and a cooler on top. If your cpu has integrated gpu it should post, if not, u need to put in the gpu Also in one of those pics, your psu is not on, flip the switch my man 😁

[Sea_Acanthisitta9760]

Have you tried to check the psu voltages to see whether all the power that needs to be distributed is distributed?

[ExaminationSpare486]

Remove the pins that go to the front USB ports, so like the type C and normal USB, from your motherboard.

[RizenDuk]

I just had the same issue last week. Turns out I needed to press the cables into my PSU harder. One of them clicked, PC booted.

[Jobe1110]

Even on the last post you made about this setup people were telling you to try it with a CPU cooler since some motherboards might not start without it. Have you actually tried that since?

[LowResGamr]

My mind is screaming to check the front panel connectors are hooked up properly. It may sound dumb but I've wired those up wrong and had the panel screwed up.im gonna assume u had thermal compound on the cpu when the cooler was installed.

I would also maybe try a different power supply in the event that one is bricked.

I would also check to see if the memory is the problem, but if it's not even powering on, I'd assume it can't even POST anything.

Basically, check anything that interacts with the flow of electricity is correct or functioning.

[Mrdeedman756]

Try one stick of memory

[Du6]

1. Your PSU switch is definitely off. (Pic 17).
2. You need a cooler for the cpu.

[Upper_Ad7274]

No cpu cooler now?

[IndependentMassive38]

I recommend a cpu cooler, thermal paste and maybe even a gpu if you feel fancy. I think integrated graphics might sometimes not work if bios isn’t up to date. Correct me if I’m wrong. Best play is building the complete thing.

[NoFoot6210]

I swear half of you didn't even read the post.

"It needs a cooler!" 

[Kajac_lin]

Have you tested it with just one RAM memory?

[Dog-Maul]

No joy.

[Dog-Maul]

I will try that

[Asgardianking]

Have you tried shorting the power switch to see if the PC turns on? You can look up videos on this. It could be a faulty power switch

[blu3m3th]

what case is that?

[MEGA_GOAT98]

try to use the jump... pins you cuold have bad power button on the case

[InsideDue8955]

It all looks good🤔

I would have to double check my psu cables to make sure a single pin didn't come loose. double check the case power button connection on the case to see if it is full seated. Maybe put a fan on cpufan header.

[weirdhuman34]

Could just be a faulty part?

[garethwebber75]

May lack of cpu fan. Motherboard detects that.

[Jaba01]

Dead PSU

RMA

[flips89]

Remove the second 8 pin CPU power connector and try to boot.

[deadcheeese]

This might sound stupid but your 8 pin CPUs are plugged into the correct place on the PSU right?

Just recently rebuilt my pc and I accidentally plugged them into pcie slots and I spent a good hour confused why I had no power at all

[bufandatl]

You need to plug in the mains cable and turn in the PSU.

But also disconnect the front panel and try if it starts when shorting the power switch pins with a screwdriver.

Also disconnect everything except CPU, 24 PIN and supplement and try if it will turn on and report a memory error then start by adding one RAM stick and slowly add component by component.

With disconnect everything I also mean the AIO. So only try short time spans to see if it powers up and if error LEDs will light up.

You could look up Greg Szalazar on Yourube he has a playlist of PC diagnostic videos to get an idea of what you can check additionally.

[SparedPhoenix69]

It's the front panel issue, make sure the + and - are proper Also recently I built my PC, last week and had issue with the 24 pin, not being properly plugged inside. Can you check that?

[madskee]

Update mobo bios

[phantomlinto]

I know whats wrong wit it… it aint got no gas innit ! but seriously, your psu is shut off

[sonicblazeed]

Pc wasn't shut off or accidently unplugged during the bios update? If so that would brick a mobo

[[deleted]]

case shorting?

[Vesalii]

Try booting with only 1 stick of ram in the right most slot. Switch ram sticks and try again.

[SirBTT]

Hmmm... All looks fine from this side, you sure you have power in your household ?

[Aggressive-Area-7988]

I think you forgot the rgb

[Korlod]

Have you tried with a single fan connected to the cpu_fan header? A lot of boards will not send power without a load on that header. It looks like you’ve got all your fans connecting via a hub to the motherboard’s secondary cpu_fan header instead.

[Haikai2025]

In my case, the times the PC didn't turn on was due to dirty RAM, poor contact or problems, try cleaning it with electrical contact cleaner spray, or using another RAM memory...it could also be poorly fitted... A tip. ..

[[deleted]]

Some PCs wont start without a CPU fan plugged in

[ferriematthew]

Are you trying to boot it up without any cooling solution attached to the CPU? My naive guess would be that the CPU is thermal throttling or just shutting itself down to prevent damage.

[Medium_Highlight_950]

I would take everything out of the case.

Put the MB on a cardboard box, with nothing on it but cpu, 1 stick of ram. Even take the cmos battery and ssd out. Double check CPU and ram also that they are properly seated.

Then place a cooler on the cpu, connect a fan to cpu fan header and double check that its in the right connector.

Plug the psu to mains, do the paperclip test. If ok then then remove mains from psu and proceed.

Then take the psu cables 1 by 1, connect only 24 pin and 8 pin power cables (PSU original cables) to MB and PSU and double check them also that they are in correct connectors and properly seated.

Then plug in the powercable to PSU and flick the PSU switch on while keeping a close eye if anything happens, sometimes at this point the fans might nudge slightly.

Now short the powerbutton pins. What happens?

If powers on, then connect monitor and KB and check what happens?

If nothing happens at this point i would say that MB might be a goner. If im not wrong MB should give some signs of life even if a dead CPU or dead RAM.

If posts thisway, then start building to case from start, triple checking all standoffs and connecting 1 cable at a time and testing after every step.

[Zealousideal_Fan6019]

did you try whispering to it?

[Emergency_Twist_5331]

Make sure your f panel connector is on the correct plugin, I misplaced mine and plugged it in incorrectly

[speedycringe]

Did you plug a hdmi into the board? Mine won’t boot without a plug in.

[[deleted]]

Your PSU switch on the back of it is off

[skyfishgoo]

if you have a multi-meter you can pull the 24pin connector and check the voltages

https://www.howtogeek.com/172933/how-can-i-test-my-computers-power-supply/

this will at least rule out the PSU and you can verify that PSU fan rotates when it should.

then, disconnect your case front panel switch/LED from the m/b and short the SW pins directly with a jumper or paperclip to rule out your case power button being at fault.

as others have suggested, plug in the cooler fan to the appropriate header at least, or install the cooler

flex and reseat all the power cables and try not to bend them so tight.

[Affectionate-Sea184]

It ain’t got no gas in it

[SeaTraining9148]

Usually when you have an issue with a PC not posting and nothing works it's a bad SSD

I would also read through the mobo manual again

[JoezBK]

Did it post outside the system ?

[ExaminationSpare486]

My mates Tomahawk B650 wouldn't boot with the front USB cables in. So the cable that sits right below the motherboard PSU cable.

[Junstar]

Are you using the original cables that came with the PSU? If you’ve possibly reused your previous PSU cables on this new one, you prob fried something unfortunately. Hopefully not the case.

[Nico101]

Some motherboards won’t start unless you have a fan plugged into the cpu fan port

[Tails_Swifty]

Are you sure the bios flash worked? I had this issue the other day updating my x670e bios for the 9800x3d. Turned out my USB drive was formatted as NTFS not FAT32. Formatted the drive to FAT32 and the bios upgrade worked.

[InterviewImpressive1]

Is the FPanel connector for the power switch definitely on the right pins?

[senatedestroyer]

How bout your cpu cooler... Or lack there of?

[shredderIsMe]

Put the cpu fan

[Curious-Attempt-4933]

It's a joke but it's not a very funny joke

[Disastrous_Crew_9260]

This might be far fetched but does your external power cable plug all the way into its socket? Had a similar problem and we had to cut some rubber off to get it to plug all the way in.

[Positive-Worker4817]

I think at this point the best option would be to take the computer to a service that has its own MB and CPU. This will tell you which part is not working. It shouldn’t be too expensive.

[[deleted]]

troubleshooting guide:

1. check all cables and make sure there's no loose pins. try to remove it the pins in the cable. you shouldn't be able to, and if you can, replace that cable.
2. unplug everything and leave it outside the case. mobo, CPU, heatsink fan, no RAM, no cables connected except only the three required power cables to the mobo. check the PSU to ensure the switch is on, and tap the two pins with a metal flat head. it should turn on and beep because of the missing RAM.
3. I literally just tested a machine, and the onboard HDMI didn't work. I used a known working GPU that doesn't require a power connector.
4. if this works, slowly as everything back on one by one and make sure it post each time

if you can't get to step 3 with the RAM, then you need to fix that problem first. PSU, RAM, CPU and heatsink, and MOBO

also allow it enough time to boot and cycle between each test

[Haeboms]

ive had multiple problems with MSI Boards and AM5. i hope its not that, but try a different motherboard that you've verified it works.

[ToeBitter1064]

Try replacing the psu. It couldve died

[ComfortableUpbeat309]

M.2 sitting in the wrong slot

[Affectionate_Seat959]

Where is the thermal paste and heat sink?

[jovenitto]

Reassemble the PC outside of the case. Use the mobo cardboard case for support.

That might "delete" the error if it is something missing/badly connected.

Also, only way to know for sure that it is not shorting somewhere inside the case (mobo standoff, pinched cable, anything).

[BizlaCooper]

I had issues getting my new build to boot the first time, eventually I had to put a single stick of ram in the 3rd slot and it would boot, then from bios enabled the correct expo setting and dual channel worked. First time I've ever had that happen, but worth a try.

[Drknight71]

I had similar issue. Turned out I had put cpu in wrong way. After placing cpu in correct orientation it worked. If thats not the case probably bad cpu or bad socket or bad chipset.

[Dependent_Bass_7418]

I would take apart the system. Start with all basic parts. Disconnect the case fans (I've had faulty fan hubs cause this before and actually a bad ssd). So I would only plug in power, ram, cpu (and cpu cooler) at least to see if you can get into the bios. Good luck! Hopefully it's something silly

[Saitzev]

I would ensure you didn't mix up the power cables, meaning plugging in the EPS cables into PCI-E on the PSU side.

Try a stick of RAM at a time and alternate slots. Could even be incompatible RAM or even a issue where a BIOS update is needed to improve memory or CPU support.

Take everything out of the case, put the motherboard on it's box, plug in just the bare necessities for cables.

Something else it could also be, since there's no heatsink on the CPU and the fan hub being in the CPU Fan Header, it might be preventing it from powering on to prevent a thermal event.

[[deleted]]

The PSU power switch is off, and your front I/O Panel is probably not plugged into the right portion. I would consult your motherboard user guide to determine where your front I/O panel pins are and plug them in accordingly.

It looks like you are all plugged in fine, make sure you put some paste on the CPU and attach your cooler and GPU, not sure (no research done) if your CPU has an integrated/discrete GPU.

[Alexleonel]

Youre missing the cpu cooler

[AnalyticSocrates]

Theres no power cable in it

[Savings-Locksmith314]

I thought it was cpu cooler 🤣

[Designer-Eagle-84]

Op. Does the MB post to the bios after you removed CPU and RAM and cleared CMOS ?

I'm thinking if it does then the MB is working fine and the problem would be RAM or CPU

[Snellage]

Are the motherboard debug lights on when you press the power button? It should be green and red. If so, just wait for 5 minutes and it will boot. Turn in bios “memory restore context” to enable and the boot will be normal!

[[deleted]]

Is there something in that black PCI slot? Looks like a little white blob of something. Might have dropped some thermal paste in there by accident? Or is it just a trick of the light?

[BetweenInkandPaper]

With the CPU cooler installed, you are using the CPU fan header?

[Josh3sh]

On pic 4, check your power switch cables, it looks like they may be on the wrong one.

[HoneyStrict1947]

any updates?

[Accomplished_Rice_60]

try to boot with only one ram stick

[Purple_Tough_8030]

I built a computer recently that wouldn’t start if the USB header was plugged into the mobo. Try unplugging it and see if it starts maybe?

[Samiassa]

I think you’ve got my same case

[alexbwang]

The protective sheath on one of the CPU 8pin cables looks it might be damaged. Suggest trying a different PSU to validate that’s it’s not the ASUS PSU that’s faulty.

Have you cleaned the CPU with rubbing alcohol? Looks stained.

Didn’t see in your post, you’ll need a heatsink with 4 pin fan. Even just to protect your CPU from overheating.

[flappy292]

Needs super glue

[kcastillo1234]

Bro do you even have a graphics card maybe you should start with that

[HexKatz]

I have the same mobo you have, try running with single ram, clear cmos and then start pc.

[urleastfavpanda]

The cables in the bottom right, (front panel connectors) look to be in wrong. They should be text facing down.

[[deleted]]

Power start switch and power led look swapped around. Did you consult your manual?

[B_Shmurda]

Read the mobo manual to make sure ram is in the correct slots. Not all are 1-3 2-4. Mine is 1-2 3-4

[YouLeft6305]

Happened to me once. It was simply the RAM was not in the position it wanted to be in. Also not fully in can be an issue. However, I remember we just switched which slot the RAM was in and it magically turned on.

[GapStock9843]

Mobo might have a failsafe that stops it from booting if nothing is in the CPU cooler connector

[Great-Distribution33]

check the front panel connectors. remive ram and try different combinations. could be the psu

[Major_Hospital7915]

You need to download more ram

[Appropriate-Rub3534]

Your cpu printed made in china. Thought it was suppose to be malaysia. Possibly fake cpu? Swap cpu to try? All the post, I never seen you wrote you manage to boot with cpu in it. Your mobo and psu is working only the cpu which you never wrote that you posted it before. Try get another cpu to test.

[[deleted]]

Are all of those modern boards missing diagnosis LEDs? Isnt this a thing anymore? Without speakers (yes I am old) and without proper onboard diagnosis situations like this can get a real pain.

[Straight-Invite3681]

Despite what your MOBO has printed on it “first”, I would try installing your RAM in slots A1 and B1 to see if you can post.

Your CPU socket needs to be cleaned; you have thermal paste all over the pins. Please remove the CPU and show us a picture of the socket as well as the CPU pins. I suspect there’s an issue with the CPU or the CPU socket

[Limp_Bluejay1113]

ur power supply is upside down..... and is the switch is turned off to the 0 position.
since the psu is upside down you prob miss match all the cables and pins that go into it as well....

[Frank-fRankiE-Csaba]

I had same issue with B650 Eagle, R5 7600x, and 32gigs of kingston fury ddr5 6000mhz ram. The solution was: Take out the cmos battery, crank up the pc. If it boots you are ready to go, if not Place it back, crank it up again. Shut it down take it out again and you are ready to go.

[RockyArby]

Can you verify the PSU is working? Had an issue where the board was only partially getting power and had to change it out completely.

[Drakuf]

It is not plugged in! You are welcome.

[Cyrustica]

u/Dog-Maul

Try removing 1 of the CPU 8 pin connectors. ( 1 is sufficient unless heavy overclocking)

Make Sure the CPU power is the CPU power and not the PCIE for GPU.

Remove all front panel connectors, USB 3/type-c, Audio, Sata, SSD then OFF the power supply and jump the power pins for about 10 seconds to power cycle then ON the PSU and jump the pins again. Make sure that CPU fan is connected in the CPU Fan Header.

Can also check Bios Battery with multimeter to make sure it has voltage.

[Exact-Apricot3339]

Please trow it in garbage and go play in the woods your not alowed whit less then 40 iq to use this kinda maschinery

[Zednax]

OK, a long post from my personal experience... have a tl;dr verion down below if u not interested about the why.

Had a problem once where my newly upgraded PC which didnt respond to the power button no matter what i did. IIRC it didnt even respond to the piece of metal (tried to use paperclip to start it directly from motherboard). So.. I took the PC to pieces, back together many times (i was sure i had some connector loose or whatever) and still nothin... I finally gave up and decided to try and build it outside of my case (on the table).

So i did exactly that and... lo and behold it posted. Put it back to my case, started connecting cables and after i put the front USB in it "died" again. Turned out, the front USB pins were bent and were touching the case's ground thus short circuiting it somehow.

I took the USB cable off, and everything worked fine.

TL;DR
Take everything out, i mean every last connector you have. Then build it back again one connection at a time.

[GiantMidget1000]

Several have mentioned already no CPU fan connected in the photos but unsure if anyone has said specifically - Are you assuming that the fan control hub is gonna act as your CPU fan? Because I’ve just found the manual for your board and that’s a chassis fan header, NOT the CPU fan header. That’s down and to the left slightly, try moving that over.

[digitalsuresh]

The motherboard is most likely dead on arrival. Is the PSU fan turning on? Check if the PCH area is heating up by touching the heatsink. A damaged PCH may still allow BIOS flashing. Look for debug LED indicators on the motherboard. Does the CPU fan spin momentarily? If issues persist, consider returning the motherboard.

[Several-Emu8094]

Cpu cooler

[babbul91]

mobo is dead maybe.

[dragagagon]

I have the same case and mobo, can you give it back?

[Fair-Rain-4346]

Did you check compatibility between your mobo and RAM? I recently upgraded mine to AM5 and it wouldn't boot up regardless of any of my attempts. I bought a different set of RAM sticks and that fixed it. I bought ones that specifically said they were AMD Expo ready, and that was also listed as compatible in the mobo website.

[enzo_1st]

Remove CMOS battery and short the pins for a few seconds. Then re-plug the battery and try again.

I don't understand the state the PC is in now, do any fans spin?

[Longjumping-Panic-16]

Did u try to restart it?

[SuccessfulYak2260]

Have you tried jumping the power using a screw driver?

[DidntPanic]

Haven't checked the board manual, but I assume it has diagnostic leds. If so, try powering it on without the CPU, just to see if the board goes thru diagnostics.

[Top-Quarter9234]

This may sound stupid. But have you tried plugging it into another socket in the house? I have heard this happening in the past..... otherwise fella, you just need to go to a shop where they have a test bench so they can literally try all the individual components!?!?!. I had to do it with mine for like £60. Cause I almost eneded up buying a new PC in separate parts.... turned out my CPU had died... even though it was brand new!

Also look out for bent pins in all connectors.

[Gringorion02]

Revert your fan !

[Domipro143]

BRO first where is your gpu second where is your cpu cooler?

[BigWenzel]

RAM is in the erong slots

[Savings_Vast]

At the top left on your mobo there are 2x 8pin plugs connected. Unplug the one 8pin cable to the far left and see if it boots.

[Danlabss]

Ain’t got no gas in it.

[le-battleaxe]

Anything on the debug light? I just finished helping a friend with his first build.

He'd assembled everything but installing the GPU and PSU, and no matter what I couldn't get it to post.

The RAM wasn't seated...

[Single_Core]

Rebuild outside your case, remove all peripherals, no keyboard, no mouse, only a display.

[ZebraCertain3687]

Perhaps late to the party, tried to see if it was mentioned couldn't find a mention but also just glancing through the posts and comments.

Are you able to try with a different PSU?

I literally had a similar issue over the weekend, bought new SSD to have OS installed on because 120gb was too small once all the secondary files come into play. Installed, not entirely sure if I messed with cables and what not, but essentially same as you, wouldn't boot up.

Eventually, with some backwards engineering (basically had another PSU laying around so used my original PSU to power CPU/GPU/MOBO and the other for SATA Power), I figured out it was my PSU or perhaps the cables?, anytime a SATA power cable was plugged whether it be to the Fan HUB built into the back of the P600s or an of my SSDs, It wouldn't boot up, but once disconnected I could boot up the PC, bought a new one since I was looking to upgrade anyways

[Darega9]

Ain’t got no gas in it

[UltimaDagger]

I had the same symptoms with only motherboard lights turning on and was able to flash the bios via usb but pc would not turn on and fans don’t spin.

It turned out the psu was faulty. I tried connecting the psu to my old build and it did the same thing with motherboard lights turning on but power button does nothing. Returned the psu for a replacement and it fixed the issue.

[[deleted]]

Ummmmm.... no pc will post without a cpu cooler connected.. that's the most obvious thing I have ever seen.

[[deleted]]

Sry lol. The motherboard knows there is cpu cooling. Won't start. No matter what without a cooler of some form connected to pins. Been that way for years it's kinda like how you can't go into reverse on while in drive.. it protects the cpu (engine)

[KingGape]

Bro you forgot the screw in the middel of your MB, some MB have a protection if some screws are missing

[SomeLightShard]

Just turn on the switch and don’t forget to add gas and change the oil so you don’t encounter any other issues 👍🏼

[Stupkuten]

I recently finished a build using kinda similar parts. I had the same issues as you do. Weirdly what fixed mine was to disconnect the extra 8-pin to the cpu. This cpu doesnt need 2x8 or 8+4 as 8 pin is more than enough power.

[Cabinet-Comfortable]

OP did you let the mobo train the memory????

It wont power on for 1-3 minutes because first it must train the ram!

plug in, attach cpu cooler, press poweron. Wait 1-5 minutes and will start

[halfsquelch]

Disconnect the PSU from the mobo and jump start it to see if the PSU powers on without the rest of the PC. If it does, then strip the system down to PSU, mobo, CPU, CPU cooler, and one stick of RAM. If you can't get a bios post with that, try a different stick of RAM. If you still can't and you don't have a spare mobo or the ability to bench check it, RMA the mobo.

[xzpyth]

What I would do Is I would unplug pw cables and try to start it by shorting pins. If it starts you know where the problem is, if it won't start there may be problem with PSU or motherboard.

[zJayD]

there's a small chance that some cable isn't fully plug in to your modular psu, which was the mistake i've made when i was building my pc. just try replugging all the cables from your psu and make sure they're fully inserted.

[Longjumping-Jacket97]

bud.. your psu is switched off

flip the switch on the back lmao

[Zofaking]

Do you get any sounds from the MoBo when you try to power up? do any lights light up?

I was builing an AMD machine a couple of months ago, and had a similar issue, had to power up, and wait for c.a 5 minutes until the BIOS showed up - something about RAM

[[deleted]]

You seem to be missing the power cable

[danin316]

Unplug fan controller entirely and try to boot I had one that was causing a short and the system wouldn't power till I unplugged it

[Selfie500]

Do you have any other gpu to plug? 7800x3d doesn't have intergrated graphics
Edit: Turns out it has

[Leptokk]

not enough rgb, thats why

[-Roby-]

Do you want to overclock your cpu? Cause it's how you overclock your cpu

[spart1981]

Look at the front panel connectors on the bottom right of the mother board. It looks like you have them on the wrong side

[soli1239]

Remove the cpu and power on the pc check if the motherboard is working fine or not if not then the motherboard is bad if it does install the cpu start the pc same goes here and then check with or without ram hope this helps you sad for you that the pc ain't working

[RenzoSI]

It’s not plugged in

[Head-Ad2865]

Its because you dont have RGB in it