Router red - losing connections

We had a series of power failures recently and my home network has since been behaving strangely. All devices have been reconnected but the extender is still giving me problems. All lights are green except for the router light which is a constant red. The extender is connected directly to the router by an Ethernet cable. I have reset the extender and router several times. I can connect to the internet through the router (very week signal) and the extender (very strong) but there are times when the extender drops off. I have ring devices, PCs and TVs connected to the extender. There have also been times when the extender has had an amber "device" light. Up until the power issues I had no problems. I've also talked to the FIOS help desk with the possbility their router is screwed up but they tested it and said it is functioning OK.