1 red light flashes on and off said contact costomer support code at the bottom e73

Hello sir

E73: General Hardware Error: Ethernet port... this error is caused by a problem with the Ethernet port.

Turn on unit until the red light flashes and the error code(E 73) shows up on the screen. Next insert toothpicks in the back of the console(while unit is running) into the cooling fans, this is to suppose to overheat the console and start two red lights flashing. Turn off console when this happens(unplug all cords from console) and turn the system back on.

e73 is an input/output error. Hopefully you are still under warranty. Contact Microsoft at Toll free: (800) 4MY-XBOX or (800) 469-9269. If you are outside of your warranty period, I believe they will still repair it for $99

HI. This is an Ethernet port issue.

E73: General Hardware Error: Ethernet port... this error is caused by a problem with the Ethernet port. Try using a new Ethernet cord. If the error continues after the new cord is used, contact Microsoft for a repair ticket. the port will need to be replaced. (Internal connection failure)

Possible solder break

Hi sir

E73: General Hardware Error: Ethernet port... this error is caused by a problem with the Ethernet port.

This is an error code for an Ethernet issue. There are people who quick fix the problem on their own, but it will void your warranty, so I wouldn't recommend it. I'd contact Microsoft support and get it fixed through them. You may have the option of getting another warranty after you get it fixed.

X-clamp Fix. Also make sure you have all four heat patches attached to your memory chips. If you don't have any buy some. They sell them on the net.

usually with 1 red light errors, there will also be an error that shows on the screen like e73, e74, e75, etc. You will need to first get your secondary error code.

then enter either the e-code from the screen or the secondary error code into the repair guide

which light is it? (xbox hd facing up)
/ \
\ /

anyway.
http://forums.xbox-scene.com/index.php?showtopic=484726

What is the error code at the bottom of the screen & check for flashing red lights on the power button if 3 illuminate it the infamous RROD(Red Ring of Death-google it) which you will get a free repair for if its the bottom right quadrant flashing red then its most probably E74 or E61. E61 is a hard drive related problem so try playing without it, & E74 is the AV cable snapped inside or the GPU/CPU inside the xbox 360 has weak solders on it, I suggest MS support ASAP.