LS4Boogy

Jus a few days ago my ex called me up to come by and i only went in for about 10 minutes. I come back out my car wouldnt start. I checked the battery and that isnt the problem. Not sure if its the alternator cause i did just get my high pressure hose replaced due to power steering leak. I tried 3 days now to crank but no luck. I jus hear only one tick once i turn the key and thats it. Please if there are any experts that can help me figure out this problem i would gladly appreciate it...