Odd power button issue

devitol

Hi John,
I received a return from eBay. I believe the item is mine and none of the components were swapped but I have a weird situation: the power button doesn't work and the sleep light doesn't light up nor does the computer go to sleep. I found the two power pads on the logic board and the computer does indeed power on and the trackpad and every key appears to work properly except the power key.

Any troubleshooting tips?

Thanks

John

I'm confused -- how can you know that all the keys work if you powered it on via the power-on pads? I ask this because the topcase/keyboard ribbon cable must be disconnected for the computer to be powered on via the pads, so I don't understand how you managed to test the keys.

Sounds like a case of liquid damage to me. They probably got the keyboard and/or power button area wet, which shorted out the electronics that would allow the power button to actually power the machine on. Just because most or all of the keys "appear" to work doesn't mean the topcase hasn't suffered liquid damage. You most likely need a new topcase/keyboard/power button, or at least a new keyboard/power button, if you're feeling adventurous enough to dissect the topcase. Take a look at my unibody MacBook keyboard disassembly video if you haven't already, because it discusses the topic.

Also, and this is a longshot, but you might want to open the machine up, and remove the actual power button from its assembly, and trying powering on by pushing the button itself (not the button on the topcase, but the actual pad that the topcase button triggers). It's conceivable that the hardware inside the topcase is not lined up correctly, and so pushing the topcase power button is not causing the actual pad to be depressed.

Thanks!

John

devitol

Thanks John. So I replaced the IR cable and the computer sleeps once again. The keyboard is definitely working minus the power button.

I used tweezers on the two pads in green in the picture below:
http://i1088.photobucket.com/albums/i322/devitol1/9586b58e-1.jpg

John

I don't get it...the power-on pads should not be able to be triggered while the keyboard cable is attached. Are you connecting the keyboard cable AFTER you trigger the pads? What model machine is this?

Like I mentioned, you might want to open the power button assembly, in case there is a mechanical reason it's not being triggered.

devitol

Thanks John, I'll try that next. I'm not disconnecting the keyboard while triggering the pad. It's a MacBook unibody A1278 from 2008.

tylr6024

Just browsing the site and saw this question. When I was messing with a few MacBooks a month or so ago I could power them on with the pads no matter if the keyboard was plugged in or not. Just thought I would add that to clear up any confusion.

John

Interesting...it must vary depending on model, or it might have something to do with the degree to which the keyboard is damaged. I've definitely had some unibody machines that would not power via the pads if the ribbon cable was connected.

devitol

Thanks for the tips. I swapped the case and the MacBook is working great again. Luckily I found a cheap case for it but all in all still an expensive power button ;-)

John

Great to hear it's working!