hi all …i have RB1000 and yesterday i had this problem in it ,the problem that its fail in boot no beep sound in it and just the blue led is lighting and I get no response via winbox ,not any of the Lan ports are responsed ,i tryed to change the Ram but it’s still not work …is this problem deal with the bios of the RB ,???
no replay,so my RB 1000 going to Dump* 
,i will going back to my RB 333 my old friend it didn’t disappoint me for more than 3 years 
What kind of output do you get on the serial port?
Have you tried to run Netinstall to install a new ROS image?
Does it boot up OK after a power cycle?
Tom
I have same state of RB1000, there is no message on seriál console, any way how resuscitate them? Blue led light on, and if connec any ethernet it is linked.
What works for my RB1100AHx2.
Situation: no beeps when powered on; network boot doesn’t work.
Solution:
- Remove top cover (6 screws).
- Refer page 3 of this document to locate reset button http://i.mt.lv/routerboard/files/rb1100ug.pdf (It near to microSD slot).
- Hold reset button and plug power cable.
ALL SETTING WILL BE RESET. No backup = no luck. - If everything goes ok, you will hear some beeps.
- Plugin ethernet cable to port 1.
- Winbox to 192.168.88.1 (don’t forget to set ip and mask to your ethernet card. DHCP will not work).
- If everything goes ok again, you will be able to connect to your router.
Go to System > Routerboard. Press Upgrade button and confirm. - Reboot your router. (Not hard reset by unplugging power!)
- If everything goes ok once again, router will boot normally.
Guesses: looks like router fails to upgrade RouterBoot, so you have to boot it in something like safe mode and upgrade manually.
Some extra words for Google: RB1100AHx2 RB1100 unbrick firmware reset