Mac OS Leopard can not be found

[Milady]

First, I have searched the forums and found problems similar and tried all their troubleshooting techniques to no avail.

I have a Macbook and I was installing ubuntu on an external hard drive connected to my mac (w/OS Leopard) when the computer prompted me to restart to finish the install. I did, and the grayish screen pops up after a minute with the question mark folder blinking. I have tried safe mode as well as option and reseting PRAM, and nothing happens.

Now, when I insert my ubuntu disc into the drive, the macbook will read it so that I may run the operating system. Through ubuntu, I can view the Macintosh Operating System which still contains all of my folders and documents. I can not copy them to an external source or access them, just merely know that they are there.

I do not have a Mac Recovery Disk and am confused on what to do in order to get Leopard to load so that, at the very least, I can retain my files and documents before starting over again.

Thank you for any information or help that you can offer!

P.S.

Using ubuntu, I found:
Name: vmlinuz
Type: link (broken) (inode/symlink)
LinkTarget: boot/vmlinuz

That file can also be found in ubuntu. Is it overriding my Leopard boot file? Again, I can not delete it, just view it through ubuntu

P.S.S.

Tried exchanging hard drives and using the one with Leopard as an external, still could not be found.

I can see all my pictures, videos, and documents from ubuntu, just can not access them.

Considering actually installing ubuntu after reswitching the drives back to normal so that I may possibly retain my files.

Update:
I also tried a hardware test by holding "d" as the macbook turned on. The question mark folder still appears.

Solution:
1) Remove internal hard drive,
2) connect external usb port to same hard drive,
3) plug into another Mac OS system as external hard drive
4) Repartition to the same amount of memory used before (Format without erasing files)
5) Reinstall hard drive and boom!

Playing around and testing does work, at big risk...

 

[Satcomer]

Can you boot into OS X's Single-User Mode (since you know Linux) and see if you can do fsck on the Mac partition?

 

[lactoseintolrnt]

I too ran into the same issue - installing Ubuntu to a USB flash drive rendered my 15" Macbook pro unable to boot. Holding down Option provided me with a blank gray screen (pressing 'N' here would give me the option to Network Boot, which I have no ability to do). After trying Verbose, Single-User, and all of the other boot-time commands as well as verifying permissions and repairing disk with the OSX Install disk, I was ready to give up and re-install as others have posted.

As I was getting ready to re-partition and re-install, I decided to try changing the size of my main partition in Disk Utility. I changed the partition size (don't delete it, just reduce the size) and added another very small partition in the newly-empty space. Lo and behold, after rebooting my system was back to normal. I think that I'll copy the Snow Leopard install disk to this new partition - just in case.

Good luck.