I know that this is an old thread but the video card can be reflowed again. We have done this with our 9 zone SMT oven with success on 10+ iMACs. The fix does indeed work. Reballing the GPU is not required. Been working for weeks to date. The bars are gone and the machine is once again stable. Some claim that this is a temp fix but keep in mind that it likely took years after the initial purchase for this failure to surface. Also strongly blaming the caking up of the heatsink compound on the video card and CPU for these issues. We are removing the old heatsink paste / pads and replacing with the latest and high grade pads from T-Global (Taiwan) - digikey carries these in varying grades. The thermal properties is much higher than other off brands. After the process, notice how cool the back on the iMAC enclosure is as compared to before this exercise.
Hi. Found this thread through Google to understand what is Error 35. Apparently a new tool is being released by JC (Shenzhen, CN) to fix this error code. However, the fix requires the removal of the NAND flash device and their tool (BGA110 P11F) to be released in January.