Thank you for the link, but I already have a copy of this manual. As well as Nokia N9-00 RM-696 Service Manual L12 v1, v3, v5, and v8.

I was also thinking of checking the antenna.
The place I took my N9 for service was a franchised company called CPR, Cell Phone Repair with a Red Cross in their logo. I would not recommend them as they used cheap Chinese parts. The replacement display they used was coming apart in my pocket, and when I showed it to them they refused to honor their warranty and claimed I dropped the phone. So I went on Yelp to write a review of them and discovered several bad reviews of the service using cheap parts that fail.

So I purchased a display on Ebay and replaced the display myself, which was pretty easy with the tools that came with the display.
The phone looks rather easy and straight forward to disassemble.