Why won't my MacBook Pro power on?

I disagree, that guy is an @%^ and will charge more than the board is worth! $325 to fix a $250 board would be a bad idea. This will only be worth it if DIY is possible.

If you want to replace the board, jump on eBay and type 820-2879.

If you want to fix the board, first thing's first is to get a schematic and boardview for this board! This is an 820-2879, you will search by that number. A boardview will allow you to check for voltage at test points I will be giving you. For example, if I say check for voltage on F7040, you need to know where F7040 is. In boardview software, you hit the C key, you type in f7040, and it shows you where that is. A schematic is a diagram of the circuitry and tells you what the components are, the boardview shows you where they go

Before buying a new board or attempting board repair, let's make sure it isn't just the keyboard. try shorting SMC_ONOFF_L to ground to see if it turns on. This is what the keyboard power button does! You will find the SMC_ONOFF_L pad right next to the trackpad. This is a good picture of where these are, short them with tweezers or a flathead screwdriver. Does it turn on? UNPLUG EVERY COMPONENT BUT DC IN BOARD AND FAN BEFORE YOU DO THIS!!!! http://www.insidemylaptop.com/images/Mac...

Take a picture of it and point to where the corrosion was. I know you cleaned it, but you remember where it was, and if you show me where it was I can tell you what to do.

Of course, you can measure for PPBUS_G3H, PP3V42_G3H, PP5V_S5, PP5V_S3, PP3V3_S5, PP3V3_S3 with the charger plugged in and the battery not plugged in. In boardview software, hit the N key, type in any of those, and measure for voltage; it will show you everyplace that that voltage is supposed to show up on the board. Measure at any one of them for PPBUS_G3H, PP3V42_G3H, PP5V_S5, PP5V_S3, PP3V3_S5, PP3V3_S3. Black probe on screwhole, red probe on section of the board where they are supposed to show up.

Also let me guess and say there was corrosion by the LCD cable.