Asus Prime B450M Only Working In Single Slot

Pip01 · October 4, 2020

Here are my specs before jumping into this:

CPU: AMD Ryzen 5 3400G

GPU: Radeon Vega 11

RAM: Adata XPG 3000MHz CL16 (AX4U3000W4G16-BSZ)

MoBo: Asus Prime B450M

PSU: Corsair CX450

Cooling: Enermax Aquafusion 240MM Rad

As the title says, I bought an Asus Prime B450M motherboard brand new off of eBay (it was being sold through Newegg but advertised through eBay) After waiting 8 days for the motherboard to arrive, I put everything together for me to run into an issue where the motherboard only posts with a single RAM stick inserted. I even inserted two sticks to no avail. Four sticks did nothing and neither did three. However, I noticed that if I switch the single stick RAM to each individual slot, it seems to work fine as long as there is only one stick in. I updated the BIOS to vers. 2203 which is the latest BIOS revision, reset the CMOS I don't know how many times, went into the BIOS and even tried enabling D.O.C.P. for the rated memory speed (which caused the system to restart three times before reposting into the BIOS in safe mode) and even swapped CPUs. I switched to a Ryzen 3 1200 and Radeon R7 370 I had lying around and still the same problem. I even switched the RAM out for some G.Skill Fortis (F4-2133C15Q-32GFT) with the same problem persisting. I feel stupid for throwing the box away before testing everything to make sure it worked beforehand so I don't think I can return it. I have read it could be something to do with possible Asus software or just bad DIMM slots but I don't know. I'm running into dead end after dead end with this.