Laptop hard drive "disappears"

Hi-
 
I have a Samsung laptop with two internal hard drives. My boot drive has twice now "disappeared," meaning the laptop freezes and then on reboot I get the "operating system not found" message, after which when I run chkdsk it gets to the very end after 4 hours or so and says "an unexpected error has occurred" or the drive doesn't show up in a drive listing at all. I replaced the drive when it happened the first time and the PC ran OK for a couple weeks, but it happened again this weekend with the replacement boot drive.
 
Does this indicate something wrong with the motherboard? RAM? I checked that the drive connection was tight and I do have backups but I don't want to replace the drive again only to have this happen with a third drive. I have some diagnostic software I can run.
 
Can whatever's going on actually damage the drives themselves? I've never had anything like this happen in years of using desktops, but I need to resolve it ASAP because I'm not getting any work done :-(!
 
All info much appreciated. If I don't respond right away it might mean it's happened again!
 
Thanks-
 
-Susan

I have gotten that error with my SSD and it fixed itself by either simply shutting down and restarting, or popping in a Windows repair disk and shutting down (not repairing, because it was the wrong version on the disk). This happened maybe 7 times in a 3 year period.
 
Two things with mine - first, my SSD had a firmware update that was a PITA to install (Patriot Wildfire), so I ran for 3 years without it - however, I do not think this was the issue (and may not be for you either).
 
Second, the Master Boot Record (MBR) can get hosed and is on a hidden partition. I recall you asking about imaging an old drive and if the MBR was included it may not jive with the new drive. I reloaded this system from scratch last July and specifically formatted both partitions to ensure the MBR was gone, and not seen anything similar since. There are utilities to dig into (and repair) the MBR which gave me a temporary fix, but the issue didn't disappear until a clean installation.
 
Are your problem drives coming from an image of a previous drive? If so, was the MBR part of the re-imaging?
 
Not saying this *is* the issue, but if the drive is not seen, the MBR is a possible suspect.

I played with Macrium Reflect to test it on restoring an image (and posted that somewhere here). Macrium had a utility to repair the MBR, but it didn't work, so I resorted to using my O/S DVD to begin the installation cycle only to do the formats. The O/S installation exposed both partitions so I was sure to wipe the MBR (also quick format). After that format I shut down and booted from the Macrium Reflect Recovery DVD, restored the image, and all was fine.

Jim Roseberry
FWIW, My step-daughter had a similar issue with her MacBook Pro.
Apple Store thought it was a defective HD.  We replaced the HD (same issue).
The problem ended up being a defective SATA (small ribbon) connector.  

Hi Jim-
 
That sounds maybe right to me, so I guess I'll go hunting for a replacement. I inherited this laptop from my Dad: Samsung Series 7 Gamer NP700G7C-S01US 17.3-Inch Laptop.
 
It's working again, but the boot drive is literally hanging out of the laptop chassis and resting on my desktop since it's such a PITN to put it all back together in case I run into the same problem again. Is that a bad thing? I honestly don't know how people with larger fingers than I have work with these things. It's like doing microsurgery.
 
Thanks-
 
-Susan