I am NOT an expert - just fully loaded with other peoples input(s). My summary of best inputs / conclusions / experiences follows:
Problem is a Sony design error with the Blue LCD and an acrylic IR filter lense on that inside the light engine.
Sony Cares' says
no new parts (sorry) just a replacement set so I got a new XBR-65HX929 for $2500 plus tax to my door. Picture is great so far. One half the weight of the 70" XBR2 and only a little smaller screen.
My Sony Repair Center (local) says a NEW light engine with the design fixed (correct glass IR filter lense and blue LCD) is $1300 (all new parts - everything ... the whole light engine) plus come out to install - another $400. This seems like we need a new cam so repair desk suggests a short block. Sounds familar. It is also LESS than the new XBR-65HX929 I just paid for.
'Sony Cares' says "no replacement parts". Sony Repair channel says "a fix is available" - albeit a totally new light engine inclusive of the design fix.
Repair your own light engine via
http://tristatemodule.com/default.aspx is about $300 if you send in YOUR existing light engine. They advise no fixes made to the design - just replacement of failed parts from older used light engine parts. My guess it will happen again w/o a fix. They have said as much.
Other
actual fixers for existing light engine with the updated engine design via sites or repair places are unknown to me but I sure would like to find a GOOD place to FIX my XBR2 light engine with the (now?) correct Sony design, glass IR filter and new blue LCD. Good specific directions for the
70XBR2 would help too on removal and reinstall of the light engine assembly.
So there you have where I am.
Anyone know a verified fixer with the correct OEM pieces as outlined?

SP