Factory reset for canon t3i - Canon EOS 600D Rebel T3i Digital Camera

Contact Canon directly to request the manual.

Which day ? Don't forget that April 11 1954 was the most boring day in history.

Go into the Menu, Go to the ninth Submenu folder, Sec one from the end, Then Go to clear settings, Third one down, Hit set, Then Clear all Camera Settings. TC Camera Repair.

yes it is compatible

Not sure this is enough, but here they come:
Delete settings:
Choose the wrench tab (top of the menu page) then choose delete settings. then press the (set) button.
Delete camera settings:
In the same menu tab, you also find delete the camera settings.
There press the (set) button. This will change everything you ever changed in the camera, back to the initial settings. I could not find e general reset.

You're in the wrong section. Remove any and all batteries and start from scratch and reset day date time etc.

Quantaray makes lenses with a variety of lens mounts. Assuming the lens has a Canon EF mount, it will fit onto the T3i just like any Canon lens. If it has a different mount, you'll need an appropriate lens mount adapter.

Try a factory reset. In the menu go to the third spanner and select 'Clear settings'

To pop up the flash put the camera in manual mode (M) and press the flash release button and it should pop up.

You may download the manual and more here.

Register your camera directly with the manufacturer.
If you bought it in the US, go to http://www.canonusa.com
Under the "Consumer & Home Office Tab" select "Product Registration".

If you bought it elsewhere, go to http://www.canon.com
Select your country or region and go from there.