Dell Precesion 3551 - Driver Errors in Device Manager after motherboard replacement

Have you tried updating or reinstalling those drivers… right click on each and select update software. After each one wait a minute or two, updating one will usually also update an "Unknown Device".

Or download originals (for your operating system)… chipset, USB, system, audio, video, network, etc from like here and reinstall… https://www.dell.com/support/home/en-ca/product-support/product/precision-15-3551-laptop/drivers

Thank you. I was able to get this resolved by re-imaging the device and running all driver and Windows updates.