Since a week ago, the player doen't want to read bluray discs. It reads the dvds but not the bluray discs.

More than likely the lens that read dvd discs has failed. On blu-ray players, there are two (2) optical lens. One reads blu-rays and the other dvd/cds. They are independent of one another.

There's no such thing as a 'BluRay DVD'. There are BluRay discs, and there are DVDs. Are you saying it doesn't read anything at all?

probebly a bad laser. sometimes they will play music but not dvds or even the other way around. from what iv read this is happening to people in just a few weeks.

Get a disc cleaning kit and run it in the machine to clean the optical pickup lens. Let the unit dry out for about 10 minutes and try your disc. Also, make sure your discs are not region specific and all scratched to hell or dirty. If that don't do the trick then you gong to have to open this puppy up and replace the optical drive as it has given up the ghost. If your still under warranty, then take it back to the shop and have them deal with it.

Cheers old chap.

Digital discs cannot be played in this unit. You can only play blurays and standard DVDs.

there must be some problem with the reading lens. try to dirt clean it if you could access the lens.

here is the specs on that drive .. it does not support blu-ray ... so you are right .. looks like acer gave you the wrong drive .. hopefully they will replace it with the correct one .. you can burn DVDs with this drive so its a nice unit, just the wrong one ..
http://support.dell.com/support/edocs/storage/197276/spec.htm

the bluray laser is bad. The PS3 has two lasers – one to read bluray, another to read DVDs. Games are in the bluray format… as well as your… well, bluray movies.
Or, this might be the issue.
If your PS3 is under warranty, send it in for repair. Describe the issue, and they will give you an RMA. I once had my PS3 repaired and back to me within the week.

the PS3 laser has two wavelegths at 405nm(bluelight) and 750nm (redlight). the highpower lower wavelength diode on your machine im afraid has failed. The bluray light reads bluray games and bluray dvd's. the lower power red light reads audio cds and regular dvds/dvdrs. you need to install a new laser ..only 100 i charge or 160 from sony (150+TAX+2 week wait+frustration from not playing COD4..lol)
Now if you have the newer model laser KES410ACA, then you have 2 SEPARATE light sources...these tend not to fail as often. it costs the same to fix

See if a DVD works. For me, I know my Bluray is ruined because I can watch DVDs and play PS2 games fine but anything Bluray does not work. If a DVD does not work, you have more of a problem, if DVD does work you need a new BlueRay which Sony should take care of for you. If you don't have receipt, etc. like me you can buy a new Bluray (KES-400AAA) on Ebay and use this guide to install it http://edpsystemssupport.com/index.php?option=com_content&task=view&id=29&Itemid=45.
Hope that helps.