13" aluminum unibody, 2.0 or 2.4 GHz Core 2 Duo processor.

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EFI Firmware possibly corrupted?

Howdy all,

Hope someone like Mayer :) has an answer for this one.

I've got a 13" 2008 Unibody Macbook, 2.4GHz. At startup, it behaves as if it's performing a firmware update: Press power button, SIL comes on, blinks rapidly about 10 times, then I get one long beep (about 2 seconds). The SIL stays on, then about 25 seconds later, I hear the chime and the Macbook boots up normally.

Everything works: WiFi works, fan is running, all RAM is recognized, etc. A restart or shutdown will take us back to square one again. I've checked the machine overview, and the Macbook is reporting the correct EFI Boot ROM and SMC versions for this model (Macbook5,1).

The RAM is known to be good RAM (pulled from another 2008 Macbook on my workbench) and is the correct speed for this Macbook (1066MHz, PC3-8500, Apple Branded RAM).

Is there a way to force the Macbook to flash the firmware again, in the event this firmware is somehow corrupt?

If so, which Firmware Restoration CD version do I download? None of the CD versions on the Apple website (1.3 to 2.0) list this particular Macbook.

Answered! View the answer I have this problem too

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Just to be clear here SIL is Sleep Indicator LED. Correct?

I don't have issues when people use TLA's as long as they define it the first time they use it. Remember, not all of us are so hip to know what your TLA means. BTW - TLA is three letter acronym :-)

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Good one, Dan. Yes, SIL = Sleep Indicator Light

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I think your system is morelikely confused than requiring a refresh of its firmware.

Let's try doing a SMC reset. Follow this Apple T/N: Resetting the System Management Controller (SMC) on your Mac. Did that fix things?

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Sorry, should have mentioned that I've already done an SMC reset and the problem persists. I've zapped the PRAM with both sticks of RAM in but haven't tried it with one, as Mayer suggests. Will do that and report back later.

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Give that a try and let us know what happens.

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If dans advice doesn't do it, pull one stick or ram and zap the PRam on the first restart

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Sorry, should have mentioned that I've already done an SMC reset and the problem persists. I've zapped the PRAM with both sticks in but haven't tried it with one, as you suggest. I'll try that later and let you know what happens. It's a little tough on the timing for zapping the PRAM, as it's hard to guess when the chime is coming after the long beep and the delay before startup . I've found that I can hear the superdrive spin up about 1 second before the boot chime, so I've been using that to time out when I press the appropriate keys (immediately after chime).

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This is actually an EFI reset (you can't do this on the newer machines. It can only be done with a RAM change and only once per change. As soon as you hit the power button, don't wait, hold down the P, R, Command and Options keys and keep holding them for three reset tones then let go. This will even open a locked machine.

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Ok, tried Mayer's advice: removed one stick of RAM. Pressed power button. Immediately held down P, R, Command and Option keys and held them down. The Macbook booted each time in similar fashion as if i wasn't trying to zap the PRAM, namely Sleep Indicator Light flashing rapidly about 10 times, then 2 second long tone, then 25 seconds of seeming inactivity, then boot chime. I held the keys down through 3 cycles of this (tone, delay, chime, reboot, tone, delay chime, reboot, tone, delay, chime reboot). I then allowed the MacBook to boot to the desktop. Then I shutdown MacBook. Press power button. Same issues as before: long tone, 25 second delay, then normal boot up. I have tested the keys when the Macbook is up and running, and all keys are recognized. The Macbook appears to be responding properly to the PRAM zap, as it attempts to reboot approximately one second after the boot chime is heard. Ideas, gentlemen?

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To be clear here, nothing has changed correct?

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That is correct, Dan. No improvement from before. Only difference is I removed one stick of RAM per Mayer's suggestion.

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