Game mode not showing any picture when i plug in my xbox 360

Connecting a controller to the Xbox 360 is one of those things that should be simple but always ends up confusing and difficult.

Wired is simple; just plug in the controller into a USB slot on the console. It should connect automatically.

For a wireless controller you do the following:
1. Turn on the Xbox 360.
2. Press center Xbox button on 360 controller.
3. Press the small "sync" button on the console.
4. Press the small "sync" button on the controller quickly after step 3.
Of course I never remember the order, so randomly mashing the Xbox button and sync buttons eventually works too. Here's a link to how to sync, but with pictures!

If you're using the Xbox 360 Universal Media remote, I believe it uses an IR (infrared) connection so there is no syncing involved. To use it you just need to point it at the Xbox 360 console (specifically, it's IR receiver). Just make sure the batteries in the remote aren't dead and that the remote is in 360 mode (as opposed to TV mode; just press the "TV" button to toggle modes).

Ensure that the audio/visual plug in the back of the 360 is in all the way, and that the red and white cables are plugged in all the way. If this doesn't work, try plugging it in to a different television. If problem persists try another audio/visual cable. I suggest borrowing one first so you do not waste money if that isn't the problem.

try using a different tv or av cables. sometimes the plugs on tvs can become loose and that is why you will hear sound but not see a picture.

they all are man made thats why they don't wrok

make sure the tv input is correct, make sure that it's plugged in correctly, and some times the 360 just freezes.

Have you tried the simple but effective, pushing the plugs in harder? And putting the 360 on its side so the disk tray opens forward and you basicly drop a disk onto the tray? And lastly have you tried pushing all plugs and everything in harder? into the t.v and 360?

ur xbox is in hd mode.to get it out of it turn ur xbox 360 on with remote than hold ( Y ) and the R trigger together and wait and see if it turns on and if it doesnt ull need a new connection for ur tv

For the most part, an XBOX will display a picture on the TV regardless of what the settings are. If there is no picture, it is most likely the cable or the XBOX output terminals themselves. 
Since you have said that your friend's AV cable didn't work either, even though it did on his, we must assume that the problem is with the XBOX.
 If the warranty is still on the console, call Microsoft and send it in. If it isn't either call Microsoft and see that they can do, or find an online repair shop that can help you.

If you need furthur assistance, feel free to ask. If this response helped you, please rate it! 
Thanks!

Here's one possiblility.

There should be a switch on the x box cable that goes from High definition output to analog.

Try changing the swith setting.

Check the AV plugs those are the red white and yellow plugs make sure that the yellow is plugged into the yellow circle on your tv and red to red and white to white, unless your on hdtv. if there plugged in make sure it is on the right channel probably 3 or 4 if those dont work change it to video mode or input mode.