This is my first post on this forum. I have the same issues on my TV and thought I should add to the discussion.
I was also about to give up on my KV-34XBR800 (purchased 3/2003). A couple of months ago, my set started having the "red burst" with the set shutting down and the standby LED blinking 7 times. I replaced IC6501 and IC8002 first during 2008 to resolve a 5-blink (?) and shutdown issue, and again this year (2011) in an attempt to resolve this red burst / 7-blink issue. In addition to replacing the ICs, I also replaced the large caps (C6590 and C6503) on the D board and a blown fuse on the A board. None of these fixed the issue (although replacing the blown fuse allowed me to turn the set on).
My co-worker suggested reflowing the solder joints at the flyback transformer on the D board and at the picture tube pins on the CX board. Just for good measure, I also touched up a few solder joints on the W board. The first 2 times I did this I saw some improvement but the red burst / 7-blink issue eventually returned. I tried again this past weekend (5 days ago), only on the flyback transformer solder joints (which I did only the first time) and the set has been working fine since. However, tonight I saw the color briefly shift greenish, then reddish, then back to normal. I also see that my horizontal convergence is off and I am now trying to figure out how to correct this.
At this point I hope to adjust the convergence (if I figure out how) then donate the set to charity, if it is still working. If the red burst returns, I'm told that it is a picture tube problem and is not worth replacing. In that case, I'll have it recycled.
I hope this helps! Good luck on your repair.
10-16-2011 Update: Unfortunately the red burst returned, so it appears that the problem is not with the solder joints. Yesterday I removed the back and the CX board and tried tapping on the CRT neck, as suggested by neccrttv in post #2 above, and will see if this resolves the red burst issue over the next week or so. It is possible that working on the set during prior attempts jostled the CRT enough that it caused it to work for a short period, usually a few days. I found an excellent reference (http://www.repairfaq.org/sam/crtfaq.htm#crtsht
) explaining heater to cathode shorts in CRTs due to metal flakes and how this might cause the red burst. Failing this, I will try neccrttv's other suggestion of replacing the red video driver IC (IC9001) on the CX board.
Regarding the convergence issue, I was able to easily correct the dynamic convergence using the service menu and adjusting the appropriate D_CONV parameters, particularly CADJ. There is an excellent thread by KenTech ("THE SONY SERVICE CODES - Articles, Comments, Discoveries") that shows how to do this and other adjustments for various Sony sets. I was also able to adjust the color and reduce the "red push" on my set, which has been bugging me for years. This AVS Forum is truly a great place for learning to repair and maximizing the capabilities of my TV.