Same issue here.

One of our E5550s (was on A21) got updated by DCU to the 5550 BIOS (A23). Somehow, all the checks in place failed and it was updated regardless. I imagine something defective with the BIOS updater. Now there is no official way to revert to the E5550 BIOS because the updater now thinks this is a 5550 and blocks the update. I've tried a few methods to skip the check but nothing has worked.

Would anyone have some insight on skipping the BIOS flash checks? I'd hate to have to purchase a warranty extension due to an issue caused by bad Dell software if I can avoid it.

Side-effects of having the wrong BIOS:

• AC adapter gets recognized as "Unknown" even though it's fine in another E5550
• Power button LED isn't functional
• Front LED indicators no longer work except for the power LED
• Only 1 of the 3 USB ports work
• WiFi will not work and many devices are recognized as unknown in the device manager probably due to the PCI-E bus being all messed up.

Exacty the same for me. I have spoken with Dell and they told me that laptop is out of warranty and they do not have any other option to revert back.

I created an account just to comment. This also happened to me, we are pushing laptops into service for teleworkers and lost an e5550 to this.

I tried rolling back and I tried installing an e5550 bios with the /s /f switches but it failed after the reboot. Has anyone successfully found a way to flash an e5550 bios?

I ran into this issue when I used Dell SupportAssist to install drivers on a Latitude E5550. But the stupid program incorrectly installed the BIOS update for a Latitude 5550, not a Latitude E5550 which is obviously wrong! Of course this caused issues like the two USB ports in the back not working, the LED light on the power button not working and the system itself now "identifies" as a Latitude 5550!

The fix is to download "5550A03.exe" and install it under Windows. Open command prompt under admin rights and run it with the "/f /r /s /foreit" switches. Wait for a few second and it will reboot and install the BIOS. I think this BIOS version (A03) has no restriction of checking which BIOS firmware you are trying to install (5550/E5550).

After that you can download "E5550A02.exe" and put it in a USB flash drive. Plug flash drive in, press F12 while laptop is turned on and select "BIOS Flash Update". Choose E5550A02.exe and add the "/f /r /s /foreit" switches and install it. Please let me know the results.

Thank you for the suggestion. I tried this process.

I was able to flash the Latitude 5550 A03 BIOS with no issue. When I attempt to run the E5550 A02 update the Begin Flash Update button is grayed out.

Same here. The downgrade works as expected but trying to flash the E5550 bios doesn't work. The button is disabled in the F12 update utility and trying to install it through Windows doesn't work either.

I might try other versions when I can find some time next week.

Thanks for the suggestion.

It is not working. From where you have this information ? "I think this BIOS version (A03) has no restriction of checking which BIOS firmware you are trying to install (5550/E5550)." 

The solution is working: I have used on two different E5550 and both of them have been moved to the correct E5550 BIOS. The big problem was that on the 2 laptops I had to follow different procedures. On the first one I have to move back to 5550A02 Bios and then apply the E5550A02. Move from 5550A03 to E5550A02 was not allowed with the error "Downgrading not allowed". When I was on E5550A02 I was able to patch Bios to the last version.

On the second machine I was not able to downgrade to 5550A02 with the same error above. I was able to install 5550A03 and from there I have applied E5550A03. Worked.

Conclusion: I believe that any motherboard has its own solution. You need to make tests with both A03 or A03 and check which one works for you.

By the way I run all of them using a DOS formatted USB. On the suggested solution there is a mismatch on one of parameters. The correct one is /forceit

Hope this could help you 

Thank you. It worked!!

I finally got it to work as well but I had to make a small variation. After getting on 5550A03, I wasn't able to transition to E5550A03 directly from the F12 BIOS flash utility due to a downgrade error message.

I had to flash it from Windows and that worked for some reason. I was then able to upgrade to E5550A23 normally and everything is working perfectly.

Thanks for the help.