Unfortunately there could be any one of a hundred things wrong with it, which is why repair shops won't even return your call: they already know theres no chance you'll agree to a $100 "fishing expedition" repair when you can buy a brand new replacement recorder for not much more than that.
It has been my experience over the last five or six years that electronics products made since 2001 do not respond well to being stored unused for long periods of time. Its as if they're inhabited by an animating force that demands attention: if you set the unit aside and ignore it, that "force" gets insulted by the neglect and vacates, rendering the unit inoperable. I've seen and heard of this happening many many times with A/V receivers, recorders, even laptops: use them or lose them. In your case, I doubt its the power supply capacitors (although that was a good guess by jjeff). The modern "failing caps" syndrome usually happens during prolonged use, as they heat up and expire, not from "cold storage" (of course its possible, anythings possible, but its unlikely). My guess is an oxidized contact in the power button, a broken fuse, or laser diode went dead in storage so unit fails its power on self check (this happens a LOT with stored DVD recorders).
Unless you're willing to pay a significant sum to have it analyzed and repaired, write off this Samsung as a learning experience. If you don't need a recorder right this minute, do not replace it or the same thing could happen again. If you DO need a recorder now, and plan to use it regularly, buy the refurb Magnavox MDR513 from J&R
. Many here have bought these and it seems to hold up very well (decent parts quality). The HDD feature is a great luxury and avoids the expense and annoyances of eraseable RW media for typical record>watch>erase use.