PC fails to post or render the display.
PC fails to post or render the display.
Build Specs:
CPU
: Intel i5 13600k
Cooler
: Deepcool AK620
GPU
: Inno3d X3 RTX 4070ti OC
Motherboard
: MSI Pro Z-790A Wifi DDR5
RAM
: G.Skill Ripjaws S5 2x16gb 6400MHz CL32 DDR5
SSD
: Kingston KC3000 2TB
PSU
: Corsair Rm850x Shift
Case
: NZXT H5 Flow
OS
: Windows 11 Home
PC was working perfectly fine for about a week after I'd built it with no issues, decided to restart windows after having trouble opening web pages on edge and since then it has had trouble starting up. The GPU was only installed on the day the issues started because it was delivered later, but it was working fine while the computer was working properly.
When powered on, all case and cpu fans start spinning but no display on monitor or lights on keyboard and mouse. Red EZ Debug LED (CPU) flashes on for half a second, followed by the orange LED (DRAM) which stays on for several seconds before turning off. After this nothing else happens and fans continue to spin with nothing on display.
I've currently got everything removed from the case and have tried powering on with every combination of installed components I can think of. Removing either CPU or RAM will cause their respective Debug LEDs to remain on.
Have reseated all power cables, RAM, GPU, SSD and CPU. No visible issues with slots, pins, headers and motherboard itself. Have used both sticks of RAM together and individually in all ram slots with no difference. Have reset and replaced CMOS battery and shorted JBAT1 multiple times, no difference. Have successfully (I think at least) flashed the newest BIOS version, reverted back to an older version, and again back to the newest version with no changes. Monitor and display cables are fine, I've attempted with multiple known working monitors, HDMI and DP, nothing from either motherboard ports or GPU ports.
I've also tested all of the 24 pin voltages with a multimeter both unplugged and plugged into the motherboard and voltages are all within specifications.
If I short the reset pins instead of the power pins on the motherboard then occasionally it will start and the red Debug LED will light up and remain on, but this goes away after being turned off and on again so no idea on that.
One single time I was able to get into BIOS but unfortunately I only had CPU and RAM installed and no access to a bootable USB drive so I couldn't attempt a boot to windows. While in BIOS everything seemed perfectly normal. I was just mindlessly powering on and off when this happened though so not exactly sure if I did anything special.
Annoyingly I don't have any spare parts that I can borrow or any laying around so I was really hoping to solve this before I buy anything, or at the very least make sure I know what I need to replace.
Any help or insight would be really appreciated, this problem has been eating my brain for almost a week now.
Begin by using integrated graphics to eliminate the need for discrete GPUs. Confirm both 8-pin EPS connectors are securely connected at each end. Ensure your cooler fan is linked to the CPU fan header; many boards won’t power up unless a running cooler is detected. If you access the BIOS, execute memtest86. The motherboard tools menu might offer this option. Alternatively, transfer it to a USB drive and boot from there. Memtest checks the CPU and RAM. Proceed only if it completes without issues.