I have the same problem from time to time due to burning various cd's and Dvd's
The - OR + sign is just the region - region as in the lens and software can only burn data etc to the disc you wish to burn to.
There can be many reasons why it is reading it as RAW.
1) as you start your system enter your Bios - the setup process for your machine, and advanced bios settings - machine's vary - enter your boot setup and DISABLE Your LG burner. and save and exit and let the machine carry on with starting. once you have reached the desktop then go to your computer to see if the drive has been disable from registry recognition. (it shouldnt be there - if it is - it will not be usable- then restart your machine.
Go back into the bios and ENABLE the LG burner. and save and exit. - and let the machine carry onto boot up as per normal. Still no change and still reads as RAW?
from www.filehippo.com - Free download not a trial etc. install and run. - this clears most of the machine's logs and debris. once you have done this follow step 3
3) goto My Computer when the My Computer window loads up click in an empty space. (right click) and a menu will appear . with tabs at the top goto HARDWARE>CD/DVD DEVICES> right click Your LG Burner and update driver- online option should be marked and the next option to install from cd should be left marked and allow it to search.
Still No luck?
As You say the Disc's Read as RAW. if you try right click on the drive - My computer - hover your mouse over the drive with the disc in that is claimed to be RAW and Right click. a submenu will appear. in that submenu should be Format. You may need to Format the disc as RAW means it has not yet been initialized - and can not be read.
The chances of the lens being damaged or the tracks inside being damaged are unlikely but shouldnt be ruled out. To save time failing the above I would simply buy another Drive.