How to loose the image ‘alt’ attribute in my custom post type?

That description-like element between the image name and the “Tweet” link looks like it is being pulled from the image alt attribute. I don’t see the code that actually produces that section– I can’t find “Tweet” in what you posted. However, you might be able to get rid of that by passing an empty alt attribute like so:

the_post_thumbnail(array('230','170'),array('alt' => ''));

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)