Hello,
I have a RB2011 at my office that is not working. When I start it, I can see on the little screen that it says “Loading kernel” but nothing else happens. I tried connecting it using the console port and accesing through hyperterminal and this is what i get:
And the screen stays on “Loading Kernel”
Winbox doesn’t detect it, neither does Netinstall.
What can I do now? 
You have bad speed. Try 115200bit/s, 8 data bits, 1 stop bit, no parity, flow control=none by default.
Ok thanks
Now I get this:
RouterBOOT booter 3.0
RouterBoard 2011UAS-2HnD
CPU frequency: 600 MHz
Memory speed: 225 MHz
Memory size: 128 MB
Press any key within 2 seconds to enter setup..
Ethernet link absent…
trying bootp protocol… failed
kernel loading failed
loading kernel from nand… OK
setting up elf image… OK
jumping to kernel code
Unhandled kernel unaligned access[#1]:
Cpu 0
$ 0 : 00000000 00000001 c7da6284 0000002b
$ 4 : c03790fc 00000d00 ffffffff c03c1bac
$ 8 : c03c5c7f c03c5c7f 00000008 2d646972
$12 : 6e672074 c03123fd 000000a1 6f206164
$16 : c7da6264 c7d6254c c7da6284 00000001
$20 : c7c21c40 00000004 ffffffff c0345ebc
$24 : 00000018 00000083
$28 : c7c20000 c7c21c10 c0380000 c01e1c80
Hi : 00000055
Lo : 00000004
epc : c01e1d08 yaffs_AddObjectToDirectory+0x114/0x188
Not tainted
ra : c01e1c80 yaffs_AddObjectToDirectory+0x8c/0x188
Status: 1000c203 KERNEL EXL IE
Cause : 00800014
BadVA : 0000002f
PrId : 0001974c (MIPS 74Kc)
Process init (pid: 1, threadinfo=c7c20000, task=c7c1c000, tls=00000000)
Stack : c7c0d000 c7da6264 00000003 00000000 c7c0d000 00000000 00000000 c01e4980
c7d01efc 00000000 00000000 00000000 ffffffff 0000001c 00000cba 00000455
000077d3 218000f7 00000000 00000000 00000000 00003494 00000000 c7c0d000
c7da6250 c7da6264 c7c0d000 c7c0d000 0000000a 0000001c c7d01efc 00000000
00000000 00000000 7fd16880 c01e7dbc c7c21d60 c0216fa4 c0338cbd c020bd2c
…
Call Trace:
[] yaffs_AddObjectToDirectory+0x114/0x188
[] yaffs_CheckpointRestore+0x1f4/0x42c
[] yaffs_GutsInitialise+0x4f4/0x1e94
[] yaffs_internal_read_super+0x6e8/0x828
[] yaffs_internal_read_super_mtd+0x14/0x2c
[] get_sb_bdev+0x138/0x1b0
[] yaffs_read_super+0x20/0x2c
[] vfs_kern_mount+0x68/0x11c
[] do_kern_mount+0x48/0x100
[] do_mount+0x620/0x694
[] sys_mount+0x8c/0xf0
[] stack_done+0x20/0x3c
Code: ae00001c 8e230068 26020020 ae030020 26230068 ae030024 ae22
0068 8e020008
—[ end trace 930d676a7edf5a5f ]—
Kernel panic - not syncing: Attempted to kill init!
Reinstal router with netinstall http://wiki.mikrotik.com/wiki/Manual:Netinstall
and instal latest ROS http://download2.mikrotik.com/routeros/5.24/routeros-mipsbe-5.24.npk
yes reinstal as honzam said.
the kernel is crashing during file system access. This can be because of damaged NAND or just software corruption of vital data or a kernel bug triggered be something unique to your NAND or data. NAND problem is the most probable one.
NetInstall should help in all cases but the situation can repeat earlier or later.
Do not enable heavy write operations tasks like saving graphing and proxy cache on disk, this will certainly ruin your NAND. Do not use FTP NAND partition for anything else then config backups.