iMac & AEBS signal strength

My network includes an iMac, Mac Mini and PC. Today, while the PC was having no difficulty accessing the internet, on starting up the iMac was unable to, showing a very weak and unusable signal strength from the AEBS. I turned off airport on the iMac, waited 30 secs, turned it on, and VIOLA had a strong signal. After months of faultless Belken performance, the AEBS may be unreliable. Any suggestions????