I have a Sentry Safe that I bought at Sam's for $150. It worked great for about 3 months and then went completely dead. I tried the batteries, playing with the contacts, all of the normal things that an electronics geek would try and no luck. I was keeping medication in there that I take every day so I needed to get in. I called Sentry support. They have an 800 number and they answered quickly and it was actually an American on the other end! I know, amazing, right? He told me all of the usual and then he said there had been some problems with the contacts inside.
The solution: unscrew the face, there is a small phillips head on the underside of the keypad. Turn the face counter clockwise and pull forward. The problem was immediately apparent when I pulled the face off. The connection that the batteries push against almost fell out. Very poor quality. There are two v shaped contacts that the battery tray presses against. Take a flathead screwdriver and bend the contacts down so that the battery tray makes solid contact and voila!
I posted this here hoping it would get indexed by Google because I didn't find it with a search. The model number is SFW123FTC. Other than this, I have been very happy with the safe. It feels well built(other the the above) and is pretty roomy. Probably great for the average family.