Woke up this morning and this three green "dashes" and three amber "dots" is what my airport express 2nd gen is doing. Wasn't broadcasting wifi.
So far hooked up over ethernet to my laptop and it passes through internet from the modem.
Tried:
Soft reset
Hard reset
Factory Default reset
All of it goes back to the 3 green dashes and 3 amber (yellow) dots. I unlike the original poster didn't apply power to the analog jack.
I will try multiple Factory Default resets and see if this helps.
Also used airport utility 5.6.1 for Windows 7 before the hard/factory resets and it wouldn't accept my well documented router password. Factory reset and now it won't connect.
Get:
An error occurred while trying to access the Apple wireless device. Make sure your network connection is valid and try again.
Error -6742
Only option is "ok" and this happens no mater what you click on for the Airport Express. Funny thing is I bought this one year and three weeks ago. Ha.
Going to try some more hard resets to see if that works. Tried to be detailed and write the text in different ways since I was unable to find this search first even though this is my exact problem 🙂 I'll try and check back later.