If U-Boot in flash fails to boot & NO output is being observed on the serial port during Power up, you can try recovery using a MicroSD Card.
For the recovery you need:
GA JSK Development board.
A Micro SD Card.
Part one, configure MicroSD card
1) Plug your MicroSD card into your PC running Kubuntu 10.04.1
Or else if you have WinXP host then go to How to recover the ConnectCore Wi-i.MX51 GA module using MicroSD in Windows XP
2) Find your MicroSD card in /dev/sdxx eg: /dev/sdb
(an easy way to find is before plugging sd card do an ls -l /dev/sd* and after plugging SD card do another ls -l /dev/sd*. You will see the newly added member)
3) cd to the folder where your uboot image is located. eg: /tftpboot
## WARNING: if by mistake you change the output device for your hard-drive instead of the MicroSD Card you will lose your system, so double check which device is the card and put it on ''of='' parameter.
4) type: sudo dd if=u-boot-ccwmx51js.bin of=/dev/sdb bs=512 seek=2 skip=2
781+1 records in
781+1 records out
400196 bytes (400 kB) copied, 0.451786 s, 886 kB/s
5) unmount/remove the MicroSD card from your PC
Part two, configure the module on dev kit
Note: Do not connect any peripheral to dev kit now. You need to detach touchscreen display also.
1) Set the boot strapping, set S8.1 to on, all others off, and all of S9 to off (Down if you are holding the board with the serial ports on the left). Also set S6.1 to on, and the others off
2) Connect to UART2 at 38400,8,n,1,n with a NULL modem serial cable
3) Connect to the module to your local network via Ethernet
4) Insert the MicroSD card into X14, power on the module on dev kit. You may see a > or P displayed on the screen, press enter and the module should boot into U-Boot
5) Copy the U-Boot image that you wanted to load on the module into /tftpboot
6) Set your module to NOT use DHCP, and instead set a static IP address by:
setenv serverip 10.80.1.130 (IP of your PC having tftp server)
setenv ipaddr 10.80.1.202 (make sure that no other device is having this IP.)
setenv dhcp off
7) Update the image:
update uboot tftp
8) If you do not get any errors, remove the SD card and set S8.1 back to off and boot the module