Yes, you can check for blank fields with the advanced search feature.
1. From the Messages, Error, Completed, Inbound, Processing, or Outbound tabs click on the elipsys button next to the search field.
2. Click on the Advanced button at the bottom of the Search Messages dialouge.
3. Provide a description (e.g. search for blank field) and then click on insert.
4. Choose a type of Custom and then past the following code in place.
var value = source.getNode('PV1-7');
return StringUtils.isBlank(value);
5. Click ok and then Search.