System not booting, no boot chime, sleep light solid on

System not booting, no boot chime, sleep light solid on

As the subject says. I can also hear the boot drive make sounds when power button is pressed. Previous threads seemed to indicate that this might be a problem with left I/O board, as previously (when system was still working) I also noticed that USB devices would not power or charge off of the left hand USB connector but would off the right. A replacement (ifixit) I/O board did not change the symptoms. Is it possible that the replacement board is also defective, or is it more likely the logic board is fried?

Asked by: Guest | Views: 208

Total answers/comments: 5

Comments display order:

bert [Entry]

"macfixblacknochime9

Rep: 181

1

1

1"

bert [Entry]

"Try Resetting the PRAM Resetting PRAM and NVRAM

1. Shut down the computer.

2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.

3. Turn on the computer.

4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.

5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.

6. Release the keys.

Your computer's PRAM and the NVRAM are reset to the default values. The clock settings may be reset to a default date on some models.

let me know if that works"

bert [Entry]

Try a SMC reset. This could be any type of hardware failure....it doesn't necessarily mean it's the logic board. I would try disconnecting the Superdrive first, then try booting up that way. You can also try removing and reinserting the RAM sticks. This can also be cause by a faulty I/O Board, and being that you had issues with the USB ports this is most likely the cause.

bert [Entry]

"I had the same issue. Tried everything here bar the teepee suggestion which i was intrigued by but went for a free diagnosis at a repairs shop before trying that one.

In my case it was a broken ram slot so it works with one piece of ram removed.

Regarding the teepee method the guys in this repairs shop have a machine that does the same thing. They call it floating it and i think were impressed at your idea of how you could do this yourself, thought it sounds like in my case it wouldn't have fixed it.

best of luck"

bert [Entry]

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.