Actually, I wasn't able to figure out, what your current problem is, so I'll have to answer to what I guess it might be.

First of all, you should have used sysupgrade to flash your board, as I suggested earlier.

That being said, let's have a look at your other (possible? As said, you were not very clear about that) issues:
- no wlan device showing up: most likely you forgot to comment or remove the "option disabled 1” line in your /etc/config/wireless
- no lan connectivity using virtualbox: to connect to the guest, you will have to add a port forwarding in virtual box for the service of the guest you want to connect to [TFTP listens on port 69, you'll find the forwarding options on the network properties page of your guest VM in virtual box], and may have to add an according exception to your host's [the windooze 7, that is] firewall

Also, your board won't be dead until you'd manage to damage the boot loader - you'd almost always able to reflash it.

But you'd really start a bit smarter: if the IP connections won't work [thus, the sysupgrade flashing method being unavailable], you should try to fix that instead of going to the next lower level (serial, boot loader 'n friends) or otherwise I already see you desoldering and replacing the flash chip in the next iteration of this approach

Report back your proceedings - I'll try to help again, if I happen to read an update here.

Hi Mopo,
first thank you to attend to and thats good news to know that my board isn´t dead.

-no wlan device showing up:
before fail trial to flash only with seriell, i could see the welcome screen and edit it successfully.
I edit also etc/config/wireless, by removing the line # option disabled 1 and adding config wifi-iface
(my router ssid and key). Reboot the board, but in ifconfig and iwconfig i missed the entry wlan0.
First i thought the changes not saved and tried to changed it again.
But etc/config/wireless looks like it should and the file was saved before.
Now, after earase the flash, my board dont boot(i could choose a operation like flash via tftp and than shows:
Bad Magic Number, FFFFFFF) So these settings i could do as recently as a new firmware is flashed

-no lan connectivity:
I checked it with 2 Systems (Notebook: Win7 Host and Desktop PC: WinXP Host, networkbridge)
both with same error. By plug in my router over lan, internet connection works fine, but carambola is not visible.

You advised me to port forward. These option i could only edit with NAT, with networkbridge its not clickable.
There i see some empty fields and dont know what to fill in.
TCP or UDP?
Host and Guest IP?
Host and Guest Port? OK think its Port 69!

Firewall in Win7 i will disabled.


If the next steps arent give a positiv effect. And have to think slowly, but surely, my board was originally damaged and broken!!! But hope dies last

Port 69 for fowarding is fine.
Don't forget that in rescue / boot loader mode, your board won't be running dhcp, so you'd have to set you computer's IP to an appropriate address (e.g. 192.168.1.2) manually.

Regarding the wlan issue, check the wiki pages.

Though there is a possibility that your board could be faulty, I'd think this would be rather unlikely.

Comments should begin with symbol "#" and not "//" ?