I also had the exact same problem a couple weeks ago. I found "the guy on ebay" made reference to earlier and contacted him. His name is Rich and his company is Same Day Auto Audio Repair Service.
He explained that this problem was due to a couple bad components in the N1 which had to be replaced (only takes a day depending on their workload). It worked out great for me because by screen/buttons went dead a couple days before I went on vacation. I FedEx'd the head unit out before I left and it was back to me by the time I got back.
On top of that, Rich called me to offer a couple upgrades (for a fee, of course). Although I didn't take him up on some of them, I did agree to pay $16 for him to replace that noisy %^&$#@ fan ...... WELL worth it!!!
So anyone else having this issue .... do a search under "AVIC-N1 blank screen" in ebay or just email him at
[email protected]. OR give them a call at 757-420-5206 (Virginia). I know it may seem like I'm associated with them in some way; I assure you I'm not. I just appreciate good service, especially when it's so hard to find nowadays.