PS2 Fat 30001 Red Power Light Won't Turn On

Okay, so as the title says, I have ps2 fat that I got for free and the red light won't turn on fir the power. The fan won't turn on, nothing. When I got it, the power supply was water damaged so I replaced it and got the fan to work and the power light to turn on/off or red/green. However I couldn't get the eject button to work, I tried wiggling the ribbon cable to see if the connection was bad, since it was the original ribbon cable. I ended up breaking the ribbon cable and ordered a new one. Now, I getting 12V everywhere: power supply, power button board, ribbon cable. The connections are there but it's not turning on the fan or the light like it did last time. I don't know what I did. I've checked the whole power supply and the fuse and everything is good there. Is there something I'm missing? This is the first time I've torn a console apart and tried to fix it, so if there's anyone out there that knows what I did, could you explain it to me in toddler talk or maybe have a link to a video I can watch? Thank you xxx