I installed a new IDE controller in PCIe slot 2, and afterward my LSI MegaRAID card in PCIe slot 3 stopped appearing in Windows 11. The LSI card had worked reliably for nearly a year as a SAS adapter for four hard drives, but now it is missing from Device Manager and none of the connected drives appear in File Explorer or Disk Management. The newly installed IDE card never appeared in Device Manager either, although it came with a small driver CD.
The GPU in PCIe slot 1, both M.2 SSDs, and all devices connected to the SATA ports on my MSI MEG Z790 ACE motherboard still work normally. I removed the IDE card, reseated the cards and cables, and confirmed the LSI card is powered through the PCIe slot, but it still does not appear. I also cannot find it anywhere in the firmware setup. It may have been removed while the computer was still running, so I'm concerned that the card could have been damaged. What should I check next, and is there a way to determine whether the LSI card itself is dead or whether this is a PCIe, firmware, or Windows driver problem?
3 Answers
Start with the basic hardware checks: shut the system down completely, disconnect power, then reseat the LSI card and its cables. Also try the card in a different PCIe slot if possible, and check whether it appears in the motherboard’s UEFI hardware or PCIe information. If it is missing from the firmware as well as Windows, that points more toward a card, slot, power, or firmware issue than a Windows driver problem. Testing the LSI card in another computer would be the clearest way to confirm that.
The motherboard’s slot layout and PCIe resource sharing are worth checking, but the fact that the original card worked in slot 3 before makes a permanent lane limitation less likely. Reset any unusual PCIe or storage settings in UEFI, update the motherboard firmware if needed, and verify that the card is receiving auxiliary power if its model requires it. Also make sure the controller and all drive cables are not being powered from an overloaded or unsuitable PSU connection.
If the controller is visible during boot or in UEFI but not in Windows, investigate drivers first: check Device Manager for hidden or unknown devices, remove any broken controller entries, and install the correct driver and firmware for the exact LSI model. However, if the card does not initialize before Windows starts, drivers will not fix it. In that case, test the slot with another known-good PCIe device and test the LSI card elsewhere. Avoid initializing or formatting the SAS drives while troubleshooting, since that could risk the data.
I was using it only as a SAS adapter rather than creating a hardware RAID array, and I cannot access any pre-boot configuration screen for it. Since it may have been removed while the PC was running, I’m worried that the controller itself was damaged.
The LSI card has always been in slot 3. I reseated the cards and cables, but I cannot find either card anywhere in the firmware settings. I may try another slot or system next.