Help reverting Back to lion after Pike-alpha hack

[B0B _Th3_Skull]

Hello i was wondering if you could be some advice about reverting back to osx lion after running yosemite in a macpro 1.1

I haveing a few graphical issues after putting in a new 5770 (monitor sleeps during boot) and can only get 800x600 out of my old 7300 after installing the 5770 and not 1080 as before. so would lilke to revert back to lion to see if that fixes the issue

 

[Ant3000]

Do you still have a copy of Lion installed on your Mac - perhaps on a different HD? If so, hold down the Option / alt key on boot and you should see the choices of OS to boot from. Or do you have an earlier OS Install CD you can boot from? I have an Apple 5770 card in a Mac Pro 1.1 and it runs fine with El Cap and Yosemite on 30" Cinema display.

EDIT: Is your card a genuine Apple card - if no boot screen it could be that it is from a PC and will not display the boot screen - this seems more likely than it sleeping. If it was sold as an Apple 5770 I would send it back or if not there are threads on here about how to get around it and possibly flash it. It should work I think but you do not see a boot screen which can be tricky.