This is the custom board based on i.MX6 processor. There are few boards (out of thousands) got failed on MFG tool. It got stuck at "Loading u-boot". This should be hardware issue. But here I would like to know, in this case, there is good chance that processor can't able to communicate RAM properly.
For debugging, can I use DDR stress test tool.. If test failed, I can say that the issue is with memory malfunction (assembly issue or any other)... Is this enough or can I do any other testing for identifying the root cause ?