I've experienced the same issue (ice maker works without issue, dispenser not dispensing water), with GE model GSF251GXBBB side-by-side.
It began 2013. To confirm water is reaching refrigerator, I located the water line up to the blue quick disconnect at the bottom of the left door (freezer side), behind grill. I removed the water tube from the quick disconnect, activated the dispenser, and there was water flowing through the tube. I reinserted water tube back into the blue collar and activated the water dispenser, nothing! That means the feed tube to dispenser is possibly freezing up somewhere inside the door. I came across a post where someone posted, to leave the dispenser light on for approximately 24 hours, to defrost water line. I tried it and it worked! May be coincidence but worked.
It appears a Burlinton NJ resident was experiencing same issue of GE fridge dispenser not working, and after having tech visit, issue was not resolved. She decided to report issue to NBC News 10 and was reimbursed! The GE reply of "out of warranty" or "issue does not apply to your particular model", did not work this time;
http://www.nbcphiladelphia.com/news/business/NBC10-Responds-Helps-Family-in-Need-of-New-Fridge_Philadelphia-383757611.html
Thought this may be helpful. Here is illustration showing where to hold blow dryer; http://www.applianceblog.com/mainforums/attachment.php?attachmentid=21687&d=1426882991
Hi opiewho, are you referring to GE Filter Bypass & Tube Assembly that was replace? Was previous part number WR17X11920 (now WR17X12512)?