I bought an Atari XEGS with box. It looks to be in fantastic condition. However, when I turn it on it does a memory test on the ROM and RAM and shows a screen full of squares. It keeps lighting up each square one by one, but it never stops. It does this both with and without a cartridge inserted. Pressing any combination of buttons does not take me out of the screen.
I took a look on the inside and I don't see anything unusual. The manual says if this test happens I should take it to an Atari dealer for repair. I was hoping someone out there may know something about how it. Just FYI, I am just starting to learn how to solder. I have also purchased a multimeter, but have not used it yet.