Blinking led lights on a WRT54G router (like Power led light) is commonly caused by corrupted firmware. Here are simple instructions you can try to resolve it, please make sure you follow this process on a computer plugged into the router directly.
1. Download the latest firmware upgrade for your router from http://www.linksys.com/download. Be sure to select the correct model version number that matches your router.
2. Assign your computer a static IP address.
3. Hold the reset button located on the back of the router for 30 seconds.
4. Next, go to Start, and select Run. Type in command and press [Enter]. This will bring up the MS-DOS prompt window. Type ping 192.168.1.1 and press [Enter]. You should get 4 replies.
5. Once you get these replies, close out of the command prompt by typing in exit and pressing [Enter].
6. Open your browser then type 192.168.1.1 then click enter
7. A username and password box will appear. Type ‘admin’ in the password box.
8. Go to Administration tab then look for firmware upgrade, then browse the file that you downloaded. The upgrade will take about 1 to 2 minutes.
9. Reset the router for 30 sec. again. Once the upgrade is complete, the router’s LED light should no longer be blinking.
Note: Be sure to set back your IP address to ObatainIP. If any of the steps do not work, or if you are having other difficulties, please contact Linksys Technical Support at 800-3267114 for further assistance.