Failed attempts before finally booting

My computer was starting up as expected until I installed two additional sticks of RAM, and now there are several failed attempts to boot before it starts up. My motherboard now has 4 slots with 4 x 48 GB each  In order to access the slots, I had to disconnect everything from my power supply, but I'm sure everything is seated properly. The only difference might be the connectors in the CPU/PCI-E area might be in a slightly different order. Not sure if that matters since they're all CPU/PCI-E sockets. I purchased the RAM kit directly from Crucial thinking I was buying the same exact modules as the two already installed, but I didn't realize that there are different versions of same model, so now I have four CP48G56C46US modules, but two are .C16B and two are .M16B1. My motherboard manual says "For dual channel configuration, you always need to install identical (the same brand, speed, size and chip-type) DDR5 DIMM pairs."  The different types are staggered so .C16B are in slots A1 and B1, and the .M16B1 are in A2 and B2. All the RAM reads and there are no problems with the computer other than the failed boot attempts, but of course I'd like get that working correctly. When it finally does boot, it goes to the black screen with white text asking if I want to F12, etc., waits a bit then it starts up. Does anyone have any ideas what might wrong, and could someone please tell me if it's less than optimal to have the two types of RAM? It seems Crucial would have specified those specifics on the product page if it mattered. Thanks in advance!

Windows 11 Pro
ASRock Z790 Tai Chi motherboard
Intel i9-14900K
192 GB DDR5
Nvidia RTX 4080 Super
Seasonic Prime 1300w
Samsung 990 Pro 1 TB System Drive

 

Edited by kalibahlu, 13 April 2024 - 02:42 PM.

Ah! Good suggestion! ;)  I will try that!

I tried it and it worked, but while I was in there, I had noticed the fan connector near the lock lever for the RAM had to be tightened, so I decided to try one more time and put the RAM back in, and I think it's fixed now. I didn't get the error message. The other thing I did while I was in there was to make sure the two power connectors from the GPU were next to each other, because I had previously not paid attention to that. I wish the cables weren't all black, that makes it hard to trace them when they're bundled. I miss the different colored ones. Anyway, I'm not sure which thing fixed it or it was just re-seating the RAM. I tried starting up twice to be sure and both times no message about failed attempts. Thanks for the tip, you really helped me out!