How to trace down to find where a field has been removed/hidden of a particular node I am using a purchased theme provided by 3rd party (it is actually a custom Drupal build comes with their modules and theme). My problem is that image fields are hidden some where in the module(s) provided by this theme.

I am sure that the apartment.field_image is not removed in the template (neither by using any hidden() function nor by non printing the $content['field_image']. I came to this conclusion by observing the $content using Devel module as well as by using standard dpm() function. That field is just not there (node content) at all.

I have also made sure its not hidden in the display settings of this content type its "image".

I have checked rest of the code by searching for preprocess, field_image and image to see if they are manipulating it anywhere. I found many processor functions which were manipulating something else like adding css etc., but but I dint find any traces where they are hiding/unsetting/removing the field.

Please guide me how can I trace it. My mind is just blowing off. Thought I would get good sleep after a week but looks not the case.
some things to look at: make sure under display, that the type of display is set correctly (full content, teaser, default, etc). Check if field permissions or similar is installed and that the permissions for that field are set correctly. Check for any rules or actions that could be causing it to be removed.

another - is it in a field collection, display settings for those are shown under /admin/structures/field collections not under the content type