Cisco 7206 Won’t boot

We recently got a Cisco 7206 Router in, and are having some problems. We have a NPE, I/O 2FE, and a 6 port E1-PRI module installed. When we turn the power switch on, the leds flash then go off. When we pull out the I/O 2FE module the Power LED stayson. Does anyone know why this would happen?