Late 2008 mbp 15" won't power on

[Porscher]

Hi, I'm having trouble with my late 2008 mbp 15". It used to work perfectly then one day I shut it down and couldn't boot it up again. I removed the battery and held the power button for about 15 seconds and tried to boot it again and it worked. Now everytime I shut it down or it drains the battery I cannot reboot it unless I do the same thing over and over again until today where it couldn't be booted up like always no matter what I did. What could be the problem?

 

[pm-r]

Will it boot up using Safe Boot Mode.

Push and hold the shift key when you hear the startup chime, then login… and test… if it boots.

 

[Porscher]

It won't power up at all, there is no start up chime. It used to work when I remove the battery and hold the power button for 15 seconds but now it doesn't. Could the power button be faulty?

 

[pm-r]

Are you booting from battery power or using an AC power adapter?

If power adapter, what color lights are showing in the connector?

Will it boot when using the AC power adapter with the battery removed?

 

[Porscher]

I tried both tha bettery and power adapter, no response whatsoever. The battery light indicator indicates it's fully charged and the power adapter lights green when connected.

I don't know if this is relevant but I upgraded the RAM from 4gb to 8gb about a year ago and that went well without any problems. Today I figured it might be the RAM so I reinstalled the original RAM back but nothing happened.

 

[chscag]

Now everytime I shut it down or it drains the battery I cannot reboot it unless I do the same thing over and over again until today where it couldn't be booted up like always no matter what I did. What could be the problem?

If the MagSafe Adapter Charger is OK (and it sounds like yours is OK) the problem may be with the DC input board leading to the logic board. That would cause the machine to act like it was dead.. no chime, won't turn on etc. You could also have a bad logic board.

Go to www.ifixit.com and take a look at the instructions for changing out the DC input board and also read through some of their trouble shooting tips.