On the left I/O board #820-2273 you will have three fuses. On the back side of the board 2 each on the upper side consequently one. These are called SMD fuses, F9800 and F7902. Color White. On eof them is pretty small. The best way to look for them is removing the Black feel off after you removed the four philips screws. The other fuse is located on the upperside close to one of the output connectors.
Read instead of: “Remove the four Y000 screws”. “Remove the four Philips 00 screws”. Thats the case what occurs to me.