Flashing cursor during attempted xp installation

Ok, I am ready to pay someone to fix my computer, but know I could fix it if I could figure it out!!! So this is my last shot.

I have a frankensteined once upon a time HP Pavilion 520n (circa 2000). I have (in times past) replaced the power unit (6 mos ago), graphics driver and processor (3 mos ago), removed a dvd player (two mos ago), and all was fine...everything worked. Now, due to what we'll call an error in judgment, I find myself replacing my hard drive, again. (I did that as well about 3 years ago) I put the new hard drive in, it is master and only item on ide cable. My CD rom is master of it's own ide cable. Pop in the disc, change bios, install goes very poorly because cd rom had a hard time reading the disc...let it "finish" but would not boot up, too many missing files. Decided to try a do-over after cleaning xp disc...computer refuses to boot from cdrom. Get frustrated and pop it into another tower and install goes fine! Except tower doesn't belong to me and of course that install won't work on my computer due to drivers etc...so, I know the disc is good, the hard drive is good, assume my cd rom is good due to initial install and was fine before the moment of bad judgment

So, pop the hard drive back into my tower with the xp disk, computer still refuses to start up from cd, if I disable hard drive to prevent it from reading that, it gives me the no operating system found message. With CD rom as primary start up, it goes through the initial checks and goes straight to flashing cursor on a black screen....have waited up to 1 hour or so for it to do something, but nothing happened...flashing cursor on black screen! Tried taking battery out of motherboard and still ended with my friendly blinking cursor.

After much research I have found nothing of assistance...just some ideas that didn't pan out! ANY help would be incredibly appreciated and make me at least feel like I am definitely at the "pay another person to make this problem go away" stage.

 

AWESOME! Got it...by accident, but problem solved. I was in the process of checking to see if the cd rom in the tower that doesn't belong to me would boot my disk (in an attempt to check if it was MY cd rom with the problem) and voila, my cd rom would no longer power on (with my xp disk trapped inside of course!) Hillbilly'ed the other towers cd rom to my computer and we are installing xp as we speak!