would that mean the logic board is fine?
Can anyone confirm what I suspect, which is that being able to run a separate disk via USB without issues would mean that the logic board is fine? Does a USB mounted external hard drive still have to route through the main hard disk controller board?
Thanks,
Zach[/QUOTE]
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No, booting from USB does not mean the disc controller on logic board is fine, the USB subsystem is a separate entity than the SATA controller. However, I had the same problem yesterday on my MBP after APPLE replaced my logic board due to failed 8600GT card, the problem was with the cable (the connector wasn't sitting flush firmly against the logic board, coming loose easily.) I was able to identify it based on years of experience in IT, but when I held my thumb firmly on the cable connector, MBP would boot, if I did not apply pressure with my thumb on the connector, MBP would not recognize the drive and flashing question mark would come up. If I removed my thumb from the connector after the os have booted, osx would start to crash with bunch of error codes within minutes.
Solution: Replaced the cable for $10, with extra tape applied over the connector on the board, it's been fine since then.
Having said all that, I run windows 7 exclusively and I just had to use osx for demonstrating the problem I was having otherwise apple geniuses wouldn't care or listen to non of what I explained. They have the general attitude that if you use windows, you're a moron or you're with the enemy and that they're the only ones in the universe who are "genius" enough to work on apple products. Don't even ask why new Macs don't have USB 3.0, just eat what APPLE puts in front of you. Apple knows what's best for the "idiot consumer". I say; see Magnuson-Moss warranty act of 1975.
Sorry, i had to went some steam as Apple Geniuses have been grinding my gears past couple days, all because I use windows 7 on MBP.