My buddy gave me his MHL adapter but it doesn't work on my phone. Am I doing something wrong?
I'm guessing the cable you got wasn't used on an S3...
Samsung changed the plug for the S3, so all other universal MHL cables will not work. Kind of a bad move on their part.
You can get a new one for the S3 for about $40, or you can get an adapter for the old one for about $15.
Yea kind of a bummer that as MHL cables finally got cheap, Samsung decided to roll with another one.
I never had one to begin with, so I went ahead and got the one for the S3. Kind of regret it now as they had a bundle for a little less that had the old MHL cable plus the S3 adapter. At least that way, the cable could work on other phones as well.
Definitely the cable. Had a similar issue with a no name brand cable. You get what you pay for.