Okay, for some reasom I thought your computer was an 800xl, my bad. I did look around The Brewing Company's website and found this:
https://thebrewingacademy.com/collections/atari-800-xl-xe-xel-xld/products/tbas-replacement-power-supply-for-atari-400-800-1050-xf551-1200xl
It's a replacement...