Dishwasher Help Needed:
The problem began when my mom's dishwasher (GE PDT825SGJ0BB) lights wouldn't turn off even after opening, closing and starting and stopping a cycle. Then it started beeping intermittently when not even in use, and then one day, it wouldn't even turn on or run (no lights on the user interface even).

This particular brand/model is known to have issues with the main control circuit board and/or UI circuit board. I have ordered and replaced both (setting them to the correct "personality") as well as the harness wiring, and even though I haven't put it back together, I would think the user interface would light up, even if just to show an error. Nothing, even when I hit the "Start" and "Select Cycle" buttons as suggested online. I have a multimeter but can't get the rods in by the appropriate wires to test the voltage without possibly cracking the casing.

We had a Sears tech out today (the washer is not under warranty but I thought they could come run their diagnostic machine and tell me if these boards I installed are any good), which was pointless. The tech refused to even touch it because it was taken apart.

So, if any of you are familiar with dishwashers, especially GE, I'd love your input. How can I test the voltage (using a multimeter or something else) to verify the correct power? Dare I attempt to have another technician out (perhaps after reassembling the machine)? Should I pursue getting the replacement boards/wires I ordered replaced? Or just suggest my mom get a new machine (which she's willing to do if need be)? Thank you!