Typically what happens is a VRM resistor isn't installed properly, and overvolts a VRM. This causes the ASICs to fail, which since they also draw from the 3.3V line, shorts the 3.3V to ground (or, well, 0.7 to 0.8V) and sometimes explodes the 3.3V buck regulator (IC102). Probably if you can identify which VRM isn't working properly (one somewhat reliable way is to see which one's outputs are shorted, or fire it up and measure for improper output voltages) and pull those ASICs. That might get the rest of the board working. I have a few here that I got from others (some overclocked, some not) where VRMs had failed and roasted a bank of ASICs, and some of them are working again on 7 banks.