A friend of mine gave me his old MacBook6,1. While I was trying to format it and run some diagnostics, I noticed a few weird problems, which I think are due to a corrupted EFI firmware. Here's what I noticed:
- Some keyboard keys don't work under certain conditions (but a USB keyboard works fine);
- I cannot hear any startup sound, but the audio volume is up and it works fine when using OS X;
- The power button doesn't behave correctly: if I press it when the system is running, it shuts down immediately. This should only happen if I hold it for a few seconds;
- Some startup key combinations don't work (either on the internal or on a USB keyboard), therefore I cannot reset the PRAM/NVRAM and the SMC, I cannot access the recovery partition and I cannot boot from an external drive. However I can boot verbose and single user mode;
- The LED on the MagSafe connector stays green when the computer is powered off, and sometimes it turns orange when it is powered on. The battery is 100% charged;
- Sometimes the fans suddenly start to spin at their maximum speed.
Of course I thought I had to reset the firmware, however I did not found a compatible firmware for this computer anywhere (including Apple Downloads).
I tried reinstalling OS X; the installation succeeded, but all these problems were not resolved. What do you suggest? Is there something else I could try? If not, since I'm not willing to spend money to fix it, I think I'll tear it down for parts. Thanks.