ahh... the memories.... staying home sick from school just to finish Zelda....
I had similar troubles with my old deck, then it just up and died. I re-soldered EVERY single point on the board, and to no avail. I gave up, because the parts are so damm expensive, (logic board was $50) they cost less new (I paid $89 for my original one back in '86). In a stroke of luck, I ended up picking one up at the salvation army for like $8. I have to admit they were really flaky decks (which is why I love the thought of a perfectly functioning emulator) My first one lasted about 2 years.
Some of the Emulators were cool, only problem I had with them was getting the controllers to react fast enough (seems like too much latentcy). I'm not sure what my problem was, but I tried about 20 different gamepads.... is it because it actually runs the gamepad in emulation? Jnes was by far the best that I tried.....
I love the Emulator idea (as far as the deck, or games not breaking) but I'd rather have the deck anyday, it's easier than setting up my Radeon's TV out, changing resolutions, setting up a 2nd mouse & keyboard to control the CPU from across the room, etc..... and besides I own about 350 or so games.....
I still faithfully play NES, SNES, Intellivision and Atari. The intellivision and Atari are the original decks that my parents bought for us back in '81, and the NES decks have been replaced about 1/2 dozen times each. Tell you anything?
I was home sick all day, and decided to boot up Metroid, and finished the whole thing....