New PC build will only boot with 1 stick of ram

[mangomagic]

I finished building my system last night and wanted to boot into the bios to make sure everything looked good only to realize the computer would power on but then my mouse/keyboard/monitor would get no signal (yet all the fans were running). The computer would power on and then restart itself and then continue doing that until I hold down the power to shut it down.
 

I unplugged everything (cpu fans, cooler fan, gpu), reseated the ATX connectors (24-pin and 8-pin) but still no luck. I tried different positions for the RAM and then when I tried booting with 1 stick of RAM I was able to boot into the bios (FYI I tested both sticks of RAM individually and they both allow me to get into the bios).
 

I tried resetting the CMOS, tried different slots for the RAM and also enabling XMP for my memory via the bios, no luck. The system still won't boot with 2 sticks of ram.

Am I missing anything or should I just rma the motherboard?
 

Motherboard: GIGABYTE Z370P D3

RAM: G.SKILL Ripjaws V Series 16GB DDR4 3000

PSU: EVGA SuperNOVA 650 G3, 80 Plus Gold 650W

CPU: i7-8700

[Princess Luna]

Hello there, try booting with the 2 sticks but in Single Channel mode instead will you?

[mangomagic]

7 minutes ago, Princess Cadence said:

Hello there, try booting with the 2 sticks but in Single Channel mode instead will you?

Thanks for the reply! I'm at work for the day but will definitely try this when I get home later. Do I enable single channel mode through the bios?

Edit: Nevermind, I will consult my motherboard manual and figure out which slots I need to have the RAM in for single channel.

[Princess Luna]

6 minutes ago, mangomagic said:

Thanks for the reply! I'm at work for the day but will definitely try this when I get home later. Do I enable single channel mode through the bios?

No you simply place the sticks besides each others on the most far right possible (facing the mobo):

 

This will have it run in single channel, if it manages to boot and all 16gb of ram is usable by the system it could be the case of excessive pressure with the CPU cooler, the i7 8700's IMC is a bit sensitive if you pressure it too much it may disable dual channel and can only run in single channel.

 

I have had this problem myself... you can just run all on single channel it makes absolutely no difference in the majority of cases(performance wise) specially with XMP up or try loosing up the cooler some trying to see if it helps re-enable dual channel.

[aries757]

i am not sure how you placed them, but try and place them every other slot, if that doesnt work try vice versa

[mangomagic]

4 minutes ago, Princess Cadence said:

No you simply place the sticks besides each others on the most far right possible (facing the mobo):

 

This will have it run in single channel, if it manages to boot and all 16gb of ram is usable by the system it could be the case of excessive pressure with the CPU cooler, the i7 8700's IMC is a bit sensitive if you pressure it too much it may disable dual channel and can only run in single channel.

 

I have had this problem myself... you can just run all on single channel it makes absolutely no difference in the majority of cases(performance wise) specially with XMP up or try loosing up the cooler some trying to see if it helps re-enable dual channel.

I'm 99% sure I tried this last night but it was late and I was very tired. I'll give it another shot later today. Do you know if I should disable XMP before trying this? Or does it not matter?

 

Also, when I installed the cooler I did feel like it was putting way too much pressure on the CPU.... I couldn't get it to boot with 2 sticks even without the cooler on the cpu. I don't think I tried single channel mode without the cooler on the CPU though. Maybe I'll give that a shot. Thanks!

[mangomagic]

6 minutes ago, aries757 said:

i am not sure how you placed them, but try and place them every other slot, if that doesnt work try vice versa

I tried 1-3, 2-4 and other combinations as well.. No luck.