I have an error message that is explained as "general". I have removed/changed the battery and memory card without results. I tried to restore to the factory default but it didn't work. The shutter will work but with no results. Ideas?
How many Shutter Actuations do you have on the camera? Maybe it's time to have the shutter looked at by your local Nikon Authorized Repair facility? My friend's D50 did the same thing - so he got a D90, but still has the 50 intending to have it fixed some day (I told him to do it fast or the shutter repair is going to cost more than the camera is worth).
I'd take it in and have them take a look at it. The D80 is a nice camera and may be worth your having it fixed (I had a D2X way back when that was getting up there on shutter clicks - it had 154K when I remember checking last and is rated at 150K... it kept going to over 200K at last heard... but back on subject, I asked my local repair shop what it would cost to have the shutter replaced when it did fail and they told me about $350 or so for parts and labor, plus anything else they may find once they get into it). It may not be the shutter though, maybe a sensor, or... I think it would be worth them looking at it (my shop looks at them for free to give an estimate, and then there is no charge if they can't make a repair as they estimated).
The problem is usually caused by as faulty plastic "rivet" that holds a metal contact switch. In this picture, the one on the left is a good part. The one on the right is the defective part. I remember I posted some photos of the repair procedure here before but I'm not so sure if it's still there.