Replaced a small daughterboard in Dell laptop; now Windows won't boot?

Hi all - just finished replacing the audio/wifi switch/USB ethernet daughterboard in a Dell latitude E6510 laptop.

The laptop was working fine before and the reason that I replaced the board was because the two USB ports on that board were broken. I put everything back together, double-checked that I had all connectors and such correctly and firmly seated in place, but when I try to boot Windows, I get the usual Windows logo and spinning dots, but after 20-30 seconds, I now get an:

"Inaccessible Boot Device" BSOD error...

......I DID have to unplug the CMOS battery when disassembling the laptop because of the way everything is put together....would that have something to do with it?

I don't know if it was set to UEFI or Legacy boot before, but UEFI doesn't work at all, and Legacy DOES start booting normally, but then I get the above error....

Any ideas what is up or how to fix this? I don't understand what changed other than the BIOS settings as it was working perfectly before I took it apart and I know everything is correctly put back together as I double-checked it all as I went with factory Dell Service Manual for the laptop...

It has a lot of specialist software on it, so I don't want to have to wipe it if I can help it....thanks for any help and suggestions!

I am not sure what Windows version it was on, but likely the one before the current 20H2.

- - - Updated - - -

YAY! Easy fix, sorted it out...sorry for posting! For some reason the reset-CMOS-default from unplugging the battery was to have RAID mode turned on for the hard drive!?!? 0_o

I set it to ATA and now all is well!

Cheers!

.....I DID have to unplug the CMOS battery when disassembling the laptop because of the way everything is put together....would that have something to do with it?

Definitely possible. Removing that battery or setting a jumper clears the User settings from the CMOS and that can affect the boot process. Might give the Optimum or Performance choice a try. If I had such a problem machine at hand I'd first remove the drive and clone it to another drive before going further. I use a drive dock that accepts 2 SATA drives and does a Byte for Byte copy without being/can't be connected to any computer and it will fail if a drive has problems.

Berton said:

Definitely possible. Removing that battery or setting a jumper clears the User settings from the CMOS and that can affect the boot process. Might give the Optimum or Performance choice a try.

Hey man! I JUST updated the thread as I was posting this - I solved it! For some reason the CMOS default is to have RAID mode turned on for the hard drive 0_o

I set it to ATA and all is now well again! :)