Troubleshooting bad parts using good Laptop

My son's GF just dropped her DV6 laptop(while in sleep mode) and it landed exactly flat on its' bottom on a cement floor from about 4 feet up. When she picked it up, battery fell out but she put it back in and hoped....
Not a scratch on it visible anywhere.
Opened laptop and not a scratch or visible crack on LCD or anywhere.

Then, pushed the ON button.

The LCD screen appears to work but you could see a myriad of cracks all over the screen, so that needs to be replaced.

Laptop would not boot and no hard drive sound could be heard. Bios HD test shows "No Hard Drive".

If it is only the HDD and LCD that are done... this laptop can be reborn for under $200. But, if something else inside is cracked or broken, it is probably doomed to appear on Ebay for parts/not working.

Would I harm my DV6, or my good HDD, if I switched HDDs with the broken one to see if the broken one boots up with my HDD, and conversely, if the broken HDD works in my good DV6?
What about memory? Can I mess up good memory if I put it in the broken laptop?

Thanks for the help!

 

Does both DV6 have similar hardwares? If yes then you can plug in the good HDD and it will boot like normal. If no it probably can't boot into windows and that is all.

No you can't mess up the RAM that way.