Revision A Tornade cart not booting after ultra bios conversion.

[cruzlink2]

Got this new generation cart I was converting for a friend that won't boot. At first it would do nothing, after I reflowed the CPU it seemed like it was trying to boot but would reset. Now I had ordered the two nand gate chips, I received one and swapped it and now it doesn't reset but just shows a solid color screen

View: https://youtube.com/shorts/nYM5-lQpEhU?si=heT70rIQVim-gHBH

View: https://youtube.com/shorts/eQPiS1xBJBI?si=CuF6Aat1EwqgUJqy

View: https://youtube.com/shorts/GL1Ujrcj9gA?si=AgxDazp5zfVSvZrU

 

[GoldenGlover]

Could the crystal potentially failing be a culprit? Otherwise I’d check the wires on the back of that A to make sure they’re not crossed/still connected.

 

[cruzlink2]

Wires are good. Any idea where I can purchase the oscillator? I know they have to be available since the repro cart use them.

 

[cruzlink2]

Swapped out the second nand gate IC and same thing I am definitely suspecting the CPU or the oscillator

View: https://youtube.com/shorts/yBRna_qKFa0?si=1a6Eklle8dkE09sj

 

[cruzlink2]

Got a parts Saturn here gonna steal one of the CPU put it in the cart and see tonight.

 

[GoldenGlover]

 

[cruzlink2]

Ok stole the CPU from a dead Saturn and reprogrammed the flash to ultra standard sh2 and we back in business. If you have a cart that won't revive check the nand chips or the CPU.

View: https://youtu.be/WmVJp9X3ocw?si=P9qYf3oqqDPA5GN9

 

[cruzlink2]

So I have a revision D cpu cart with the same symptoms and I replaced all the same things I replaced on this card and it still won't fire up at all, with that one I suspect the oscillator. @Darksoft do you have any of the oscillator you use on the repro carts left? I would not mind buying one from ya, can't seem to find them on the net.