Please help troubleshoot MBP 13"

Hey guys. I've been searching for days and I haven't gotten an answer that would help.

I bought my Macbook Pro 13" as the Late 2009 model (aluminum unibody). Nothing special: Core 2 Duo/2.26Ghz/2GB RAM/160GB HDD.

About a month after I bought the MBP I upgraded the RAM to 4GB from OWC and also upgraded my HD to 250GB. It's been running great ever since, until about 2 days ago. It just basically stopped booting out of no where. I mean i take care of my laptop like a baby so this is making me frustrated . When I turn on the MBP, it turns on, but doesn't boot. I get a Folder with a question mark in it. Don't worry i searched what it meant.

I've tried:

1) "zapping" the RAM with the commands at boot - still get "folder-question mark" icon.
2) "rebooting" with install DVD (Snow leopard 10.6) - Unable to choose a "disk" at install. Nothing shows up.
3) replacing the hard drive (formatted thru another mac's disk utility) - still unable to choose "disk" to install. Again, nothing shows up.
4) put back the original 2GB ram + 160gb HDD and went to Genius Bar - they booted mine up with their target drive or w/e it's called. Booted up fine. they told me I just needed to replace the hard drive - obviously not the case

Please help because what i think i'm doing right - isnt working.

Thanks in advance

sounds like your hard drive is dead. can you see it on another computer? does it spin up?

is your memory seated properly?

thing is i have an enclosure for 2.5" drives so when I put that drive in a plug it into my other MBP, it comes up fine. Everything is still on there.

If the hard drive you removed from your MBP boots and works in an enclosure, and the replacement drive (160 GB) doesn't work in your MBP, we can assume it's a hardware problem and not the hard drive.

Some things to check:

1. There are two insulator strips one on each side of the hard drive slot in your MBP. Make sure they're both in place.

2. The cable from the hard drive to the logic board.

Your logic board is OK otherwise the genius could not have booted the machine with his test hard drive.

Odd problem. Neither of your drives will boot it up, yet the Genius got it to boot with their drive. Either this Genius is made of pixie dust, or there's some kind of luck with the connection that you're not having or he/she did have. Make sure all the cables and ribbons are seated properly. Make sure all contacts are clean. If you have yet another HD around, try using that.

I'm so curious now. It still could be the logic board, and it might have been a fluke that the Genius got it booted.

Doug

thanks guys. this problem has been puzzling me for some time. i mean i've done this before and it's worked out smooth as butter. this time, not so much.

When I brought in my MBP to the Genius Bar they hooked up their drive to my pro, booted it up fine from theirs. They told me that my pro didn't even show my existing drive in Disk Utility (i had the same problem with 3 different hard drives that I tried booting). After it booted up he brought it out back to see if cables/board/insulators were all in place and connected. Came back out and told me everything was fine and it was just my hard drive.