DRAM 128K system has stopped working

[Ernest]

Hi Cesh,
When you get to scope stage, check out your reset circuit operation. 
Give particular attention to Cap C43.
I assume you have not changed to a different power source to what was operational before?
Changing the main input voltage too much can upset the reset.

I can loan you a test ROM if need be after your AMIGA group presentation, just call me.

Ernest