Blinking folder with question mark

Most likely the hard drive has failed.

You can try booting your OSX 10.6 Snow Leopard DVD to see if you can use Disk Utility First Aid to repair the file system. If the file system is Ok, then you can try reinstalling macOS over top of itself.

I hope you have a backup of your data because if the drive is failing, then the more you use it the worse the failure will get to where even a professional data recovery service will be unable to recover any data.

If you don't care about the data and reinstalling macOS over top of itself doesn't work, then you can try performing a clean install by first erasing the drive before reinstalling macOS. If you are attempting to reinstall OSX 10.6 and need to erase the drive, then follow these instructions to properly partition and format the drive:

https://www.owcdigital.com/assets/support/support-formatting-and-migration/Mac_Formatting_6-10.pdf

If erasing the drive fails or the clean install doesn't work, then most likely the hard drive has failed.