Perhaps it would be worth your while figuring out why you can't access the internal XRAM. Surely there's a reason. I really doubt it's a broken part, as, how likely is it that sloppy soldering, handling or whatever, would damage the XRAM?

Don't give up yet! I'll bet if you study the situatin further, you'll find the problem and fix it. Perhaps if you carefully clean and examine your circuit board, you'll learn some things, too.

RE