Macbook Pro 15"

duffling

Hi , we have an unusual issue with a Macbook Pro 15" unibody. DC board has been swapped , PSU has been swapped , power button on tested OK yet the mac fails to show any power on signs at all.

The charger lights as normal , orange with battery installed , green when charged. Power button pressed does not have any effect. No optical drive noise , No fans.

All logic board fuses test OK. At a loss where to look next?

John

Hi! How is it possible to confirm the power button is OK if the machine fails to show any signs of life when you press the power button? It sounds to me that the power button, and the keyboard/power button assembly as a whole, may be at fault. Did this machine have liquid damage? If not, what was initially wrong with it? The power button is connected to and dependent upon the keyboard, and the keyboard and power button are basically just one piece, so if the keyboard has liquid damage and suffers from an electrical problem, that can prevent the power button from working as well. Many people therefore have good boards, but no ability to turn them on because the electronics involved have gotten fried.

DC-ins are very rarely at fault, especially if there is a solid light, and it turns amber when the battery is charging...that basically tells you it's working, and I would never suspect one in that condition. And again, the AC adapter is most likely not a problem if it's got a steady light and the battery is obviously charging.

First, just to be safe, I would re-seat the RAM, then test the RAM slots by powering on with one slot empty, and then the other empty.

Next I would take off the topcase/keyboard, then disconnect the keyboard ribbon cable, and bridge the two power-on pads with tweezers or a paperclip to see if the machine powers up. If it powers up, the fault is with the keyboard/power button assembly. The easiest way to deal with that is to replace the whole topcase/keyboard assembly. Again, make sure to disconnect the keyboard ribbon cable first, because otherwise bridging the pads may not have an effect.

If you need the location of the power-on pads, let me know the year or serial number of your machine.

Thanks