Asjad
Anything can be repaired the question is it worth the time and effort.
The cost of a basic CD or DVD has reached the $50US mark. If you have a shop rate of $30US@Hr and have to buy a sub assembly for $40 plus shipping, you have cost more then a replacement.
Poking around either device , to learn is another thing. You dont have to worry about burning your eyes , just don't stare directly into the laser. It uses a visable spectrum so it's not like you can be inadvertantly harmed and there are warnings even inside the things as to HV and Laser light.
Play and have fun.