Macbook Pro not booting with its own hard drive

I have a very peculiar problem here. I urge you read through it all to understand what I have done thus far.

So, I have my mid-2010 17" Macbook Pro, right? Got it back in June (third one), and all is well. Yesterday afternoon, I was skyping with a friend and she started to blur up for a long time. I told her to do all the normal stuff, but it wasn' working. My fans were running unusually fast for a video chat, so I decided to shut it down for a minute or two and restart. Well, it turns out that last shutdown was its last.
I went to restart it, and it never got past the grey screen with the Apple logo (with the spinning circle below it). I tried to boot into my Windows partition, same thing. I tried booting to the CD, same screen. I couldn't go anywhere. I tried booting into single-user mode, safe mode, verbose mode, a probably a bunch more I can't recall. Bottom line is, this thing won't boot.
So I didn't what I shouldn't have done, and removed the hard drive from my computer so I could at least back up what I needed (172GBs.. back up often, kids). While I was at it, I removed my hard drive from my Macbook and basically swapped the two. and GO FIGURE, the MBP booted without problems or errors. It was like nothing had ever happened. When I booted up the MB, it gave me a no-OS icon, so I booted from the CD-- worked fine. I wiped and installed a fresh copy of SL on it and swapped them back.
The MB is working fine (that's what I'm on at the moment), but the MBP still won't boot. The spinning circle doesn't even come up anymore. It's just the grey Apple logo screen. I did verbose and single-user mode, and they both stop at:
"Loading System\Library\Chaches\com.apple.kext.caches\Statu s\Extensions.mkext..."
..and freezes. Computer unresponsive. Cannot type anything, at all. Yet, with this same hard drive in my MB, it worked fine.

I don't understand. Usually an unresponsive verbose mode means a problem in Darwin, but how could this NOT occur in another computer? I don't think it could be an update that caused this either (nor do I remember updating recently as I was up to date).

I have Best Buy's Geek Squad all-incident warranty, so it's not a problem getting it fixed. I just would like to not have to send it out for a week and a half if it's a simple fix.

P.S MBP HDD is a 500, MB is a 120. I'm not switching hahaha.
P.S.S My friend's MBP's hard drive is in the process of failing (corrupt detected in Disk Utility and SL disk cannot repair) and his CD drive failed in the same day. My PC is also on its way out, not even two years.
What is wrong with my house?

EDIT: I apologize if this is the wrong folder. I believe it's hardware, but I honestly cannot pin it on anything for sure.

Sounds like something that happened to my friends.

His ended up just being a bad SATA cable but his would boot from the CD.
Unfortunately, that's all I have to say that would be of any help, sorry.

If I understand what you did (your post is confusing).....

You realize that the internal hardware is different for the MB and the MBP? The operating system is specific for the model of Mac it's running on.

Normally you can not swap a hard drive from a MBP into a MB and expect it to work or vice versa. Not sure how you got the MBP to boot using the HDD from the MB?

Anyway, what I suggest is completely removing the HDD from the MBP and close the case. Then try booting it with your original install DVD. If it boots OK, then you know for sure the HDD is defective.

chscag said:

If I understand what you did (your post is confusing).....

You realize that the internal hardware is different for the MB and the MBP? The operating system is specific for the model of Mac it's running on.

Normally you can not swap a hard drive from a MBP into a MB and expect it to work or vice versa. Not sure how you got the MBP to boot using the HDD from the MB?

Anyway, what I suggest is completely removing the HDD from the MBP and close the case. Then try booting it with your original install DVD. If it boots OK, then you know for sure the HDD is defective.

Click to expand...

I realize that there is a different between hardware, yes. Usually, hard drives are not dependent on the hardware it's attached to, especially when it's wiped clean. Either way, it was just a last-minute decision I chose to do and it worked. If they were specific, then Apple would not just release a general SL disk; they'd release one for specific computers. I have used my SL disk on 7 different iMacs and 8 different laptops. Yes, it's legitimate. Point being, it's very possible. That's why I can go and buy a SATA HDD at Microcenter and drop it in without worry.

Besides all of that, I had removed my HDD and attached it via external SATA hardware and attached it to the MB. Worked fine, booted into it perfectly. Did the same with the MBP. Nothing. I tried booting from the CD on the MBP with the external removed. Nothing. It can't be the hard drive.

EDIT: I apologize for the hostile behavior I exhibited. I'm very flustered. I'm also sorry for the confusion. The problem is that my computer will not boot with its own 500GB hard drive. I've put in a 120GB and it worked fine. I've wiped the 500 and tried it again, and it wouldn't boot to anything. I reinstalled SL on the 500, and it still won't boot.

Update: I was able to boot into Hardware Diagnostics from my CD and all passed well. However, I cannot boot into the cd for any other reason.

It could be the SATA cable, as I said before.

I would just take it into Best Buy.

s2odin said:

It could be the SATA cable, as I said before.

I would just take it into Best Buy.

Click to expand...

I'm very hands-on, therefore I'm trying to solve this on my own before I send it into repair. I can't see it being a hardware problem, as it runs fine on another hard drive. However, I can't see it being a software problem because it didn't have any software on it at one point, and it still didn't run (and even now that it does, it still won't). It can't be the HDD, because it runs fine hooked up to any other computer.

I'm feeling like this at the moment:
jhasfgaesnugyqwfhasjghuehggeha

drburke said:

I'm very hands-on, therefore I'm trying to solve this on my own before I send it into repair. I can't see it being a hardware problem, as it runs fine on another hard drive. However, I can't see it being a software problem because it didn't have any software on it at one point, and it still didn't run (and even now that it does, it still won't). It can't be the HDD, because it runs fine hooked up to any other computer.

I'm feeling like this at the moment:
jhasfgaesnugyqwfhasjghuehggeha

Click to expand...

SATA cable isn't part of the hard drive.

Here's what happened to my friends:
His MBP booted into the grey screen with flashing question mark.
I put my HD in his MBP and it did same thing.
I put his HD in my MBP and it worked.
I ran Onyx and Disk Utility on his HD while in my MBP. It was perfect.
I put his HD in his MBP and it booted from CD.
He took it to Apple store, they replaced SATA cable and it booted up.

But it might not be if the MB HD works in the MBP.
I think you have exhausted all options at this point, lol

If your hands on, go to a Bestbuy or Frys (if you have them) and get a Sata Serial ATA cable. Then open your Mac Book Pro and replace it. Or just take it to Apple. Both valid choices.

s2odin said:

SATA cable isn't part of the hard drive.

Here's what happened to my friends:
His MBP booted into the grey screen with flashing question mark.
I put my HD in his MBP and it did same thing.
I put his HD in my MBP and it worked.
I ran Onyx and Disk Utility on his HD while in my MBP. It was perfect.
I put his HD in his MBP and it booted from CD.
He took it to Apple store, they replaced SATA cable and it booted up.

But it might not be if the MB HD works in the MBP.
I think you have exhausted all options at this point, lol

Click to expand...

I'm responding to both of you right now, on my MBP. With the MB hard drive. It works perfect. I'm glancing over right now. My MB is running fine, with my MBP hard drive it in. Both booted into the CD (installation and SL retail) perfect.

When my MBP hdd is in the MBP, it won't boot up worth $#%^. The MB will.

The hard drive works. I realize the SATA cable is not in the hard drive. It's attached to the controller on the motherboard. How can it be that though, when this is running perfect with another hard drive it in? It's like the keys are messed up or something.

And if I take it into Best Buy, they'll send it to Apple Repair, and for what? What will they conclude? They'll do everything I did, and might be stumped just as I am.

drburke said:

I can't see it being a hardware problem, as it runs fine on another hard drive. However, I can't see it being a software problem because it didn't have any software on it at one point, and it still didn't run (and even now that it does, it still won't). It can't be the HDD, because it runs fine hooked up to any other computer.

Click to expand...

Then why don't you try what s2odin suggested? Also, we are well aware that a retail Snow Leopard install DVD will work on both machines. What I was trying to point out to you is that the install disk you received with each machine, be it the MBP, or MB is specific for that machine's hardware.

If you wish to swap out the HDD cable (goes from HDD connector to the logic board) you may be able to get one from iFixit: The free repair manual.

Let us know and Happy New Year.