I don't know what happen it is? I just use flashtool to backup the existing rom and relash the new rom cobalt-2.10.3-ext3-1M.rom; It seem everything alright. So I try reboot normally. it prompted the kernal panic!
But The LCD startup screen is different from previous screen. OK! I try to use the RaQ550 OS to recover. Firstly it ask erase and rebuild Y/N, I answer Y, then it keep to do the partition..... After few minute it prompted as following message:

******HALT*******
MOUNT

Why? Please tell me why? :(

I found it from cobaltfacts; But I don't know what is *nix PC which allows two processes (terminal sessions)", I use WinXP with hyperterminal. Can it work?

Be careful, make sure you don't loose power while performing the reflash.
And as usual Disclaimer: I am not responsible for the use or misuse of
this procedure.

You can progam through the serial port, requires a *nix PC which allows
two processes (terminal sessions) to use the serial port at the same time.

Replace "cobalt-1M.rom" below with the filename of the rom image you are
installing. And ttyS0 assume com1 if com2 ttyS1.

Get into the ROM Menu Mode

For Current ROM > 2.9.x
----------------------------------------------------
Cobalt:Main Menu> eeprom

Cobalt:EEPROM Menu> write_eeprom
Re-Initializing flash: done
EEPROM in bank 0 is 1024KB (AMD AM29F080B)
Loading ROM image from serial port...

now switch to another terminal session and
cat cobalt-1M.rom > /dev/ttyS0
the rom will display a kbyte counter:

1024k done
Press any key to abort... 3 2 1
Erasing eeprom in bank 0: done
Writing eeprom in bank 0: 0x00100000:0x00100000 done
Verifying eeprom in bank 0: 0x00100000:0x00100000 done

Cobalt:EEPROM Menu> main

Cobalt:Main Menu> reboot
Rebooting - please wait............
----------------------------------------------------

For Current ROM 2.3.x
----------------------------------------------------
Cobalt:Main Menu> boot

Cobalt:Boot Menu> dl_kernel
Loading Kernel: -

now switch to another terminal and
cat cobalt-1M.rom > /dev/ttyS0
the rom will display a spinning char

Loading Kernel: done

Cobalt:Boot Menu> main

Cobalt:Main Menu> eeprom

Cobalt:EEPROM Menu> write_eeprom 0
Erasing eeprom in bank 0: done
Writing eeprom in bank 0: 0x00100000:0x00100000 done
Verifying eeprom in bank 0: 0x00100000:0x00100000 done

Cobalt:EEPROM Menu> main

Cobalt:Main Menu> reboot
Rebooting - please wait.............
----------------------------------------------------

Treotan:
Did you have a working install of RaQ 3 OS before?

If so, why didn't you try the PKG-ROM-Upgrade like I linked you to?

Hi! Ironfist,

Because I found many possible solution for upgrade Raq3 to Raq550, so I did try the wrong way. :( :bawling:

How I can do it right now?

Thks

Haha!!
I can reflash the rom to 2.9.36-paged.rom and install the RaQ550 to my machine. That is really great!

Thanks for you support!

How does the Romdowngrade via console work ? Can you help me please?

Greetings Phil