My AirPort Express is showing a permanent orange light. Every ~5 minutes it blinks green once and after this I get continuos yellow.
The AirPort device is connected via LAN to my Linksys WRT-160NL router that is configured with DHCP enabled - is supposed to give and IP to the AirPort.
The AirPort is undiscoverable via LAN or WiFi.
If I try the hard reset procedure, all I get is flashing yellow led after few seconds but no other effects.
Is it older than a year? AE power supplies eventually fail due to internal heat. At least one failure mode - the one I recently observed - is just as you described it. If I kept trying, I'd occasionally get a green light and Airport Utility would discover it long enough for me to set a configuration, but it would soon fail again and go back to a slow-blinking yellow light. It would happen just often enough to keep me trying to revive it, but I finally let it go after sinking a couple of hours into it. At least in the US, if it is being used with a system that has AppleCare coverage, I believe the AE will be covered too. I hope that option is open to you.
Ok, so it's now Oct 2024... and my AE has this same issue after many years of service! Tried all the resets, multiple times with no change. So.... dropped from my son's height (about 1.5m) no luck... dropped from my height (1.8m).... restarted via Hard Reset method.. and it totally works! Good luck with yours!
Take a look at the status codes article over on Apple's site.
Solid yellow - There was an issue starting up. AirPort Express will restart in 60 seconds.
This is not a permanent solution, but I have had considerable success by placing the Airport Express in a ziplock bag and leaving it in the refrigerator anywhere from thirty minutes to several hours.
Once I plug it back in, the router works fine for many hours.
As @JRobert answers it's very likely overheating, but this can push back the upgrade/replacement date for quite a while.
My AE will go to solid amber from green after operating for a period of time, usually an hour or so. I unplug the power source for 20 seconds and plug back in. It will reboot (slowly) and return to green for another hour or so of normal operation. I do not notice a difference in the amber mode operation.
This is going to sound totally ridiculous and fake, but it is not. Be sure to have tried all other solutions first. But then drop it from 1.5 meters onto carpet, on the side with the connections.
This has fixed the problem for me and countless others, as you can read here:
https://discussions.apple.com/thread/4031394
After 4 hours of troubleshooting I was ready to throw it in the trash. Without much to lose I dropped it and it works again, orange light turned green and the Airport Express (first generation, A1264) was visible again in the network and Airport configuration app.
