No power at all. Water Damaged ECU

[Nigleet]

So I bought a 2003 B6 A4 1.8. I knowingly bought the car as is.

No power at all (Its not the Battery)
No dash lights, no crank, no start, no clicking.

ECU looks to have been water damaged (confirmed dead, plenum chamber...). Would the ECU affect ALL power to the vehicle? Im assuming yes, though I've never owned any sort of German vehicle. (Jeep guy )

Hoping a "new" ECU, and maybe some relays, will do the trick. I have already looked into the ECU complications with VIN, Immo, SKC, etc. That should not be a problem, just hoping its just the ECU. Anyone have any suggestions, or been in a similar boat?

Thanks.

[imnuts]

No, the ECU shouldn't prevent other items from powering up. There should be a fuse on the + battery cable, and I would assume that if you have no power anywhere, that may need to be replaced.