How to debug wp_query?

After uninstalling WPML, something got messed up: one of my categories is not showing up any posts anymore. The post itself shows up, but the wp_query within its template file seems to be empty. I’m still waiting for WPML feedback on this, but honestly they’re not that helpful, so I’d like to know how to debug my wp_query or some sort of debugging tips (I already turned it on on my wp-config.php). What can I do? Should I look under wp_posts or something? I don’t even know where to start ??