Dos led stop working after i installed latest firmware it lights on when i reboot the router but when i turn on Dos it stays off.I reset/reupgrade but nothing.
Anyone can help me?

Is that with 3.3.5.1? If so, they changed the functionality so now the DoS LED only comes on when there's a DoS attack, which imo is a smarter way of using the LED.

Yes


Model Name : Vigor2820
Firmware Version : 3.3.5.1_232201
Build Date/Time : Nov 25 2010 12:54:37
ADSL Firmware Version : 232201_A Hardware: Annex A


Although i do believe that it was better before when the Dos led was on and blink during a dos attack is there any way i can change that?

Cheers mate!!