How to tell the difference between new deck and refurbished one?

[Desmond Lu]

I saw some websites are selling steam deck, but i dont know if its new or refurbished...

[tfk]

Define new. For me new is from the original vendor (Valve) in unopened package. A third party seller doesn't transfer Valve's warranty. So that leaves the state it is in. The only way to be sure is to buy from Valve. New or refurbished.

[Mizufluffy]

There is Valve Certified Refurbished:
https://store.steampowered.com/sale/steamdeckrefurbished/

According to Valve the only difference between those and new retail units is "minor cosmetic defects", and those are defined as "small blemishes or scratches on the plastic casing, not the screen".

Additionally Valve Certified Refurbished comes with the same warranty and customer support as new retail Steam Decks.

The only official ways to purchase a new Steam Deck is from Steam (US, CA, EU, UK) or from Komodo (JP, KR, TW, HK). Only those officially sold Steam Decks are truly new.

Source:
https://www.ign.com/articles/valve-warns-users-to-buy-steam-decks-from-official-retailers

[Man's Best Friend]

As with all products, the only way to tell new from refurbished (at least beforehand) is to only buy from authorized sellers. Anywhere else is a gamble.