i have to replace the motherboard of my DELL Precision 390 ( this PC is connectec with an analytical instrument, so it is very critical). PN is CN-0DN075-70821-7AD-70B9.
Any suggestion where i can find this board?
It has to be a used or refurbished one for that old model. Beware of private sellers with no guarantee it will work. It's expensive too so consider buying a new computer instead. That model is 11 yrs old.
What about Amazon? Also, if you Google it, various sellers come up including Direct IT.