Help needed :( Debug light cpu > dram > cpu then turns off

[Eajimoba]

Computer had been working fine, until I tried to install my 3090 today.

 

turned off system, turned off psu Power pulled out all cables and proceeded to replace my 2070 with my new gpu. 
 

Inserted my existing 2x8 pin power, added another 8pin from my psu as my gpu is 3x8pin and plugged everything back in to switch it on 

 

My msi mobo has an ez debug light and it goes from cpu>dram>cpu (all white light) and switches off and turns back on automatically only to loop the same lights.

 

i reseated my gpu

i replugged my gpu pcie power connectors both on gpu and on psu (modular psu)

i rearranged my pcie power connectors

i put back my 2070

i tried no gpu (9600k)

checked my power cables in case they moved or unseated during gpu install

only plugged in my psu power and nothing else

 

i initially thought it was my gpu problem, but then I tried my 2070 which also had the same problem, so I tried with no gpu and resulted in same problem... the only thing I had done was open case, take out power connectors from gpu, take out gpu, put in new one, and put power connectors in.. 

 

My specs

i5 9600k

be quiet dark rock pro 

msi mpg z390 gaming edge ac

corsair vengeance 2666mhz cl16

antec 750w gold psu

many advice is much appreciated! 

[thermalgoop]

PSU may not be able to handle a 3090. Antec has fallen out of favor as a PSU manufacturer in recent years. Try a Seasonic 850 or higher for best possibilities. Maybe try pulling out your drives, other components, disabling onboard devices in BIOS, undervolting CPU, and generally doing anything to reduce the power load on your system before reconnecting the GPU, to make sure it's the power delivery that's the problem.

[Eajimoba]

3 hours ago, thermalgoop said:

PSU may not be able to handle a 3090. Antec has fallen out of favor as a PSU manufacturer in recent years. Try a Seasonic 850 or higher for best possibilities. Maybe try pulling out your drives, other components, disabling onboard devices in BIOS, undervolting CPU, and generally doing anything to reduce the power load on your system before reconnecting the GPU, to make sure it's the power delivery that's the problem.

Yeah I ended up fixing the problem without actually "fixing it"

 

I removed the motherboard and set up a makeshift test bench and it turned on fine, then added in all my peripherals one by to see when it would have a boot error but it never resurfaced

 

I imagine it might have to do something with either the motherboard having a short or the pc case causing a short resulting in the failure shown above

 

I won't be buying a mid-range case anymore that's to be sure, everything is so tightly packed in there it was hell just to diagnose anything

[thermalgoop]

16 minutes ago, Eajimoba said:

 

Yeah, some cases can be less than well thought out. I've definitely had issues where conductive parts of cases touch components. How that gets through QC is beyond me. I've found Fractal Design cases to be pretty darn good for the money recently. Especially if you're going for a smaller box, I really love my Node 500 ITX.