Original post by: Charles Fisher ,
Hi there, I assume that you had only replaced that I/O board only. Now, if you had replaced any other hardware items just prior to this problem then you may want to remove them and replace them with hardware that is compatible for Apple machines. If you obtained that I/O board from places like ebay, make sure it's NEW or at least guaranteed to work as intended. You can get bad parts back to back, just make very sure that you had connected that cable from the I/O board to your logic board correctly and fully inserted otherwise, you can develop issues. After doing this, if things do not improve then the likelihood of having a failing logic board is in the works. Call Apple and inquire about this "Depot" program that's going on. What this mean is that they can repair your laptop for $350.00, they will replace whatever is needed to restore it back to full operation and that cost includes everything.