I'm seeking a second opinion about an idea. I'd like to power a Raspberry Pi from a larger computer. I can't think of anything that could go wrong with the setup I'm proposing.
Background:
I have a Raspberry Pi connected to a USB TV tuner. The tuner has its own wall wart power supply. Currently, the Raspberry Pi has its own power supply. There is an ethernet cable from the Pi to an ethernet switch. The Pi sits on top of a larger desk-side computer that is also connected to the ethernet switch. (The Pi is a go-between so I don't have to reboot or mess with the big computer when the TV tuner goes comatose.)
The big computer has a >1000W power supply that is seriously underutilized. "sensors" on the big computer says the 5V rail is at 5.09V. All equipment is usually powered on 24x7.
The problem:
The Raspberry Pi's wall wart power supply (the 5.25V unit from AdaFruit) generates enough RFI that it mostly obliterates reception of a local AM radio station at 860kHz anywhere inside the house.
Proposed solution:
I'd like to run wires from the big computer ground and +5V (with a 1A fuse) up to the Raspberry Pi's power input connector.
Why I think it should work:
The only things connected to the Pi are power input, ethernet, and USB to the TV tuner. Ethernet is electrically isolated, so there can't be ground loop issues there. The USB TV tuner has its own wall wart power supply, so that can't cause ground loop issues, either.
Question:
Is there something my analysis is missing that would be problematic?
Thanks,