いくつか F2 を打ってから F1 を沢山たたいて、数字を小さくしておいて、
その後に F2 を一回打っても、やはり落ちる。

Apr  8 05:48:33 nazuha /netbsd: abtn0: cmd(09)
Apr  8 05:48:33 nazuha /netbsd: abtn0: brightness(5d)
Apr  8 05:48:33 nazuha /netbsd: abtn0: cmd(89)
Apr  8 05:48:35 nazuha /netbsd: abtn0: cmd(09)
Apr  8 05:48:35 nazuha /netbsd: abtn0: brightness(65)
Apr  8 05:48:35 nazuha /netbsd: abtn0: cmd(89)
Apr  8 05:48:36 nazuha /netbsd: abtn0: cmd(09)
Apr  8 05:48:36 nazuha /netbsd: abtn0: brightness(6d)
Apr  8 05:48:36 nazuha /netbsd: abtn0: cmd(89)
Apr  8 05:48:37 nazuha /netbsd: abtn0: cmd(09)
Apr  8 05:48:37 nazuha /netbsd: abtn0: brightness(75)
Apr  8 05:48:37 nazuha /netbsd: abtn0: cmd(89)
Apr  8 05:48:39 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:39 nazuha /netbsd: abtn0: brightness(6d)
Apr  8 05:48:39 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:39 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:39 nazuha /netbsd: abtn0: brightness(65)
Apr  8 05:48:39 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:40 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:40 nazuha /netbsd: abtn0: brightness(5d)
Apr  8 05:48:40 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:40 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:40 nazuha /netbsd: abtn0: brightness(55)
Apr  8 05:48:40 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:40 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:40 nazuha /netbsd: abtn0: brightness(4d)
Apr  8 05:48:40 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:41 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:41 nazuha /netbsd: abtn0: brightness(45)
Apr  8 05:48:41 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:42 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:42 nazuha /netbsd: abtn0: brightness(3d)
Apr  8 05:48:42 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:42 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:42 nazuha /netbsd: abtn0: brightness(35)
Apr  8 05:48:42 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:43 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:43 nazuha /netbsd: abtn0: brightness(2d)
Apr  8 05:48:43 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:44 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:44 nazuha /netbsd: abtn0: brightness(25)
Apr  8 05:48:44 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:44 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:44 nazuha /netbsd: abtn0: brightness(1d)
Apr  8 05:48:45 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:45 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:45 nazuha /netbsd: abtn0: brightness(15)
Apr  8 05:48:45 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:45 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:45 nazuha /netbsd: abtn0: brightness(0d)
Apr  8 05:48:45 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:45 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:45 nazuha /netbsd: abtn0: brightness(08)
Apr  8 05:48:45 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:46 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:46 nazuha /netbsd: abtn0: brightness(08)
Apr  8 05:48:46 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:46 nazuha /netbsd: abtn0: cmd(0a)
Apr  8 05:48:46 nazuha /netbsd: abtn0: brightness(08)
Apr  8 05:48:46 nazuha /netbsd: abtn0: cmd(8a)
Apr  8 05:48:47 nazuha /netbsd: abtn0: cmd(09)
Apr  8 05:48:47 nazuha /netbsd: abtn0: brightness(10)
Apr  8 05:48:47 nazuha /netbsd: abtn0: cmd(89)