D-Link DL-4500 stops broadcasting....need help.

I bought a refurbished DL-4500. I've setup quite a few routers in my day but this one keeps stumping me. I've setup the dl-4500. It saves the settings and starts broadcasting and the signal holds up for a while. Then suddenly it just vanishes. I have multiple wireless devices and nothing detects it. But when i go into the routers configuration ip page it says its broadcasting. so i'll change something in the settings. Save it and there it is again as if it never vanished. and then after a few minutes gone again. The longest i've gotten it to run was like 1 hour.