It sounds like the back light went out. Some are replaceable...some are not.
I would contact the manufacturer and see what they have to say about it as this information is not that available to others than manufactures or their reps.

You can try to google for the information....

As to laptop parts there are very few reputable dealers around for that kind of part and sorry but I have not a clue on laptop parts other than the normal replacements.

If it is any consolation...I have found that laptop parts are extremely pricey and that sometimes you may just need to look at a full computer replacement as the price for parts can be that high and laptops are getting cheaper.