What text goes garbeled...? Is it the text you first see when powering on your PC (the POST process)...?
If your monitor has an 'auto' feature, try and use it. If not then it's most probably dead and you'll have to replace it.
The only possible issues I can think of besides fried circuitry are incorrectly seated video card, improperly connected VGA cable, lack of power from PSU or incompatible AGP version.
|Desktop PC| |Macbook Air 13" (Mid 2013)|
|Windows 8.1 Pro (x64)| |AMD FX 4100 Black Edition 3.6 GHz @ 4.0 GHz OC| |Arctic Cooling Freezer 13 PRO| |Gigabyte Nvidia GeForce GTX 560 Super Overclock 1GB| |ASUS M5A78L-M/USB3 Motherboard| |Samsung 840 Pro 256GB SSD SATA III HDD| |Kingston HyperX 8GB PC3-14900 DDR3-1866| |OCZ ModXStream Pro 700W Modular PSU| |NZXT Vulcan Micro ATX Case|