I recently bought a new triple-fan PNY RTX 5070 OC. My power supply is a Seasonic FOCUS Gold 750W semi-modular unit. It only seems to have one PCIe cable coming from the PSU, with that cable splitting into two sets of 6+2-pin connectors. I previously used the same cable with an RTX 3060 and it worked fine.
For the RTX 5070, I connected the included power adapter, but the card does not appear to power on, the fans do not spin, and it is not detected by the system. I have pushed the connectors in until they clicked and checked the seating, but after several hours of troubleshooting I am still stuck. I am also unsure whether using one daisy-chained PCIe cable is safe or sufficient for this card. Could the issue be the PSU cable, the adapter, or something else?
3 Answers
First, verify exactly which power adapter came with the card and how many PCIe plugs it requires. Each plug on the adapter should be connected to a separate PCIe cable from the PSU if possible, rather than powering everything from one daisy-chained cable. Also make sure the adapter is fully inserted into the GPU and that the cable is not sharply bent right next to the connector. Do not use modular cables from a different PSU brand or model.
Before assuming the card is dead, power the system off, switch off and unplug the PSU, then reseat the graphics card in the top PCIe slot. Confirm that the monitor cable is connected to the graphics card rather than the motherboard, and check that the motherboard’s auxiliary power connectors are attached. If the card still shows no lights, no fan movement, and no detection, test with separate PCIe power cables or have the retailer test the card and adapter. Fans can remain stopped at low temperatures, but the system should still detect the GPU.
A 750W supply is generally enough for an RTX 5070, but the exact Seasonic model matters. Some older FOCUS units are not ATX 3.x models and may not have a native 12V-2x6 cable, so they rely on the graphics card’s adapter. That adapter can still work, but it needs the required number of properly connected PCIe plugs. Check the PSU label and Seasonic’s compatibility chart before buying a native cable; never assume a cable from another modular PSU is compatible.
The adapter itself is not automatically unsafe. The important points are using the correct adapter, connecting all of its inputs, fully seating the GPU-side connector, and avoiding a loose or damaged plug.
The card’s fans are not spinning at all, so I’m going to check the adapter and the other cables when I can get back to the PC.