I check the configuration and all is ok. Solid red diag light means there is something majorly wrong with the router while a blinking diag light suggests a problem with the firmware. Can somebody help me to solve this problem? 11-03-2015 08:02 AM. The signal strength is always more than 75% from the main router. Tried to reset the range extender as it was not working well lately. 2. The Linksys N600 Pro Wi-Fi Range Extender, RE4100W is one of the latest range extenders from Linksys that operates on 2.4 GHz and 5 GHz frequencies simultaneously. But every minutes the green light situated in the front of the extender be red. What media players are supported by the Linksys RE4100W? The Linksys RE4100W N600 Dual-Band Wireless Range Extender is one of the latest range extenders from Linksys that operates on 2.4 GHz and 5 GHz frequencies simultaneously. The audio port lets you connect any 3.5 mm earphone and powered speaker to it. After pressing on the reset button (for about 10 seconds) and plugged it back to the socket, the light at front turned red and kept on blinking. To fix this, you must be using the latest firmware for your router or access point. Linksys range extender RE4100W. You can use it to extend the coverage of your existing wireless networks to eliminate Wi-Fi dead spots. The Linksys RE4100W boasts its wireless music playback feature. It allows you to repeat the wireless signal of any access point or router in order to provide Internet connectivity to hard-to-reach areas through a wireless connection. Blinking red diag is still salvageable by forcing a firmware upgrade or reflash but with the solid diag light all you can do with it is a reset of 30 seconds and a powercycle,if the light is still on after that there is nothing else we can do about it. Be sure you have at least 50% of your router’s Wi-Fi signal at that point on the device you used for setup. The Linksys RE4100W Range Extender allows you to stream music on your network and play it on the speakers through the audio port. If the Link LED on the Wireless Range Expander lights up red, this indicates that there is no wireless connection between the Linksys Wireless Range Expander and the Wireless Router or Access Point. After that and some seconds the light will be green again.