Showing results for 
Search instead for 
Did you mean: 

Possible faulty Z390F MOBO (or memory), advice needed!

Level 7
I just finished putting together the hardware on a new build.
CPU: i7 9700K
MEM: G.Skill 32gb (2x16) RGB
PSU: EVGA G3 850W,
CASE: NZXT h700,
MOBO: Asus rog strix z390-F

So, after putting everything together and flipping the switch on the PSU (not the case) the computer already turned on. Why could this be happening?

Also, my monitor doesn't turn on, so i can't access my BIOS. After some digging around it seems that it's some sort of hardware failure. Most likely the MOBO, but it could also be memory (the memory RGBs don't light up, every other hardware that has lights does) and less likely is that the PSU is at fault. I think. Also, my motherboards onboard leds light up this way:
red - turns on and off (cpu)
yellow - this one stays lit (dram)
white and yellow-green - don't turn on (gpu and boot)

Could it be my CMOS is empty? (very unlikely because i just got the motherboard like 2 months ago)

With all this information, does this help somebody in narrowing down the possible issue?
Thank you in advance for any assistance!!

Level 13
When you hit the Power button to turn on the system, It goes through Post (Power on self test) where your hardware components are interrogated. Once all is OK then it boots to your OS. As your yellow led is constantly lit (DRAM_LED) then this indicates an error with your RAM and post will not continue till the error is rectified and so no output to monitor.
Your first move will be to check your RAM. They are either a mismatch, faulty or there is an issue with the MB RAM slots.

You can test your RAM in another system or run Memtest86 from a USB, You can try testing RAM by using just one DIMM Module and switching into differing slots. (ensure they are seated correctly)
You should check that the RAM kit you have are listed on the MB QVL to ensure they have been tested and also ensure your Bios is updated.
We owe our existence to the scum of the earth, Cyanobacteria

My System Specs:

MB:ASUS ROG Crosshair VII Hero/WiFi GPU:EVGA GTX 1080 sc PSU:Corsair AX-1200i
AMD R7 2700X Cooler: Corsair Hydro H115i Case: Corsair Carbide 780t

Memory:G.Skill TridentZ F4-3200C14D-16GTZR SSD:Samsung 500GB 960 EVO M.2