has anyone heard of bypassing the power supply and just using DC power to run a miner?
The control board and the hash boards couldn't care less where the 12V DC comes from, so ya, you could bypass the miner's PSU but then you will have a lot of issues to deal with.
You will need to stabilize the DC input which can't happen if you want to supply the miner directly from the solar panels, and then two, you will need something to attach those 6-pin connectors to, you can't just a run couple of wires from the solar panels and attach them to the miner.
So technically, this can be done, practically, it seems like a terrible idea.