Phanteks AMP GH 850W 80+ Gold Power Supply - White

Yes, it is backward compatible with older PCIe connectors via the provided modular cables.

Yes, it includes a full set of modular cables needed for standard builds.

Yes, extension cables that connect to the end of the provided cables are generally safe, but avoid using custom modular cables designed for other PSU brands.

It means the unit is at least 87% efficient at 20% load, 90% at 50% load, and 87% at 100% load, resulting in less electricity waste.

It is a high-quality powder coat, but like all white components, it should be handled with clean hands to avoid transfer of oils or dirt.

Ensure the power cable is firmly inserted into both the wall outlet and the PSU, and verify the I/O switch on the back of the PSU is set to the 'I' position.

This is normal if the load is low. The Hybrid Fanless mode keeps the fan off to ensure silence. If the system is under load and the fan is still off, check temperatures or contact support.

Ensure the 12V-2x6 cable is fully seated in the GPU port; you should feel or hear a click when it is properly locked in.