Sony KV-34XBR910 HDTV - power supply

6 blinks is the dreaded "Low B" error, indicating a power problem related to the digital circuitry. There are two boards with related power supplies as well as the digital board(s) that could be the problem. Trial and error replacement of the boards is usually needed to track down the culprit. Hopefully you are dealing with a Factory Authorized Service Company who will only charge you for the actual board needed and not every one they have to try to get it going again.

And yes, it will be expensive, and there is a possibility that factory boards may no longer exist.

That sounds like a failed MCZ3001D chip. Nearly all failures of these TVs seem to be caused by that one problem. See these links
http://www.avsforum.com/t/1366567/sony-trinitron-wega-rlod-twenty-dollar-repair-guide
http://k0lee.com/2011/05/fixing-a-sony-wega-with-6-or-7-blink-code/

Replacing the whole power board if it is just a MCZ3001D chip failing would be expensive overkill. 2 MCZ3001DB chips and sockets costs less than $20.

It is possible the problem isn't with the MCZ3001Ds but that just isn't very likely.

Often DIYers would buy a dozen (or so) of the chips along with the sockets and swap them until the set starts working. When it stops working again, they go through their box of ICs and change them until it starts back up. Often, the previously "bad" IC might work again.

Sony seems to have designed the circuits (running at 250 KHZ) around perfect versions of the IC but any drift of components and it stops working and the manufacturer of the chips doesn't seem to have tight enough production QC.

That said, those ICs usually cause an H-Stop or V-Stop error occasionally but with power supplies running at insane speeds, the Micro is just quessing at times as to the cause of a shutdown.