Dell PowerEdge R410 - What is required for boot

Hello. I have a system with specs below.

2x Intel Xeon E5620 4c + dual tower coolers

20gb Samsung Reg ECC DDR3 @1600mhz

Dell PowerEdge R410 Motherboard 3GTGH.

A 300w Hipro out of a different dell from the same time period.

I have already followed a different thread here to modify the PSU pinout to work with this board.

I'm wandering how to get it to boot. I tried bridging all the pins to the front panel connector and this didn't work.

What all is required to boot? I assume front panel, but is anything else like a PCIe riser card required to boot.