Inspiron 3646 will not boot after bios update

1. Power off and unplug
2. Press/hold power button for ~15 sec
3. Open case and remove motherboard battery. See manual for details
4. Press/hold power button for ~30 sec
5. Reinstall battery (right-side-up!)
6. Reboot with fingers x'd

There are different levels of "Not Booting" which may be considered.  Are you not able to get back into the Bios setup or not able to boot the OS?  Knowing exactly what it is doing may help.

What Ron recommends may help and in addition you might check for a bios recovery for a failed bios flash.  It works differently on different systems.

If it is the OS which will not boot, perhaps you need to check the bios settings for such things as primary boot device or boot configuration.

The bios updates may reboot a couple of times.  It seems the system will expand and store the bios flash data and then reboot to do the flash.  It will probably reboot again after the flash is complete.  Hopefully, yours has finished the entire process.

Just had the same thing happen updating an Inspiron 3646 BIOS from A04 to A09.  Flash reported as successful but PC did not shut down and/or reboot afterwards - did nothing for 15 minutes.  My first "brick job" in 20+ years.  

Current symptoms : after plugging in ext AC supply : power switch LED is amber instead of white, CPU fans and disc drives power up, after two seconds PC shuts down, after about 5 seconds, PC powers up again with amber power LED, CPU fan spinning low speed, disc drives powering up - then it sits doing nothing.  

Power switch will not power off PC.  Machine will not P.O.S.T.  Display is black, no beeps, no nothing except power to the MB!

I've tried ALL combinations of resetting CMOS, trying the applicable Dell recommended BIOS recovery procedures, as well as a few other USB flashing procedures - so far nothing has worked for me and PC is out of warranty.  

Are there any 3646 specific procedures for BIOS recovery or is it dead for good?  Was hoping to use this box in my system here, with a new copy of WinX on the way for it.

Thanks.