Quoted your post to display the photos that were small enough to display. The forum won't display images larger than ~2MB, not sure the exact limit.

Are you checking the IO supply voltages? Once you find where either RO or CO is bad, the next thing you should do is check the IO supply voltages (1.8V and 0.8V) for that chip. The 1.8V voltage is generated by a regulator at each voltage domain, and the 0.8V supply voltage is generated by two different regulators per voltage domain. They are fed through each chip. So the output of the regulator could be fine, but the input to a chip may not be if there is a bad connection to a chip before.

If the IO supplies aren't good, then a perfectly good chip will not have good RO, CO, and CLK signals.



You can measure the IO voltages for each chip at the capacitors shown below: