No the question isn't too stupid but may I point out this is the
TSOP FLASHING SECTION
I would of thought the xploit section would have been your best bet to get an answer/possible solution asap
error 16 is a dashboard or dash/clock problem
Either it is trying to boot the ms-dash or clock needs to be set - which it will attempt to go "through" the ms-dash to setting the clock
The ms-dash ain't booting correctly, it is trying to boot but can't find it
In the past I have fixed other error 16's by using another modded xbox and hot-swapping the drives after they were booted/unlocked by xbox - risky but ok if you are very careful.
then re-do the h/d on the modded xbox
I would post your problem in the xploit section and see what they say, if you have a friend with a modded xbox then the hot-swap method is a possible solution if all else fails