Does not boot but both fans turn at all times

When the problem started, the MBP would not boot when the on button was pressed but 10, 15 minutes or 1 hour later whenever it felt like it... Now, it doesn't boot at all, no sound, no chime, nothing but the fans come on and stay on as soon as the battery is connected or if the magsafe is plugged in whether the battery is connected or not and without pressing the on button.

After a while, even though the MBP has not booted and even though the fans are turning,, the machine gets hot, I can definitely feel the heat underneath, on the lower case. The only way to stop the fans is to keep the battery unplugged... I obviously can't reset the SMC because it won't boot. I've tried a few things but nothing works so far. I'm afraid the motherboard is fried. The green and orange light on the magsafe adapter work fine so I doubt the IO board is to blame. I took out the IO cable,

checked it and cleaned it as well as the connectors on the board then plugged it back in but it didn't do any good... If anyone has an idea, feel free to pass it on... Thanks guys