So my NUC still seems to be dead. I was trying to contact Intel Support from the link in this page : http://www.intel.com/p/en_US/support/warranty
I am getting a blank white page at the Online Warranty & Support (all customers) link. https://servicerequestmgmt.intel.com/webticketui/private/warrantystatus.aspx?lang=en-us
Also the SSL certificate of the site seems invalid. Way to go Intel.
It seems that the NUC you have is defective, it could be possible that during the BIOS update the memory controller was corrupted therefore the 3 beep you heard.
My recommendation still is to contact Intel Customer Support for warranty replacement of your NUC . You can use our Chat system to do that.
Chat support: http://www.intel.com/p/en_US/support/contactsupport
Thanks for the reply.
The chat support seems unavailable.http://intelsupportchat.force.com/icslivechat/ics_tech_desktop_ww_english_Chat
Is there a support window during which I can contact the chat support. Thanks.