Incident Caused By Inserting CPU Cable Into RTX 4090 Connector
Incident Caused By Inserting CPU Cable Into RTX 4090 Connector
Hello
I mistakenly connected the incorrect cables to my RTX 4090, which clearly wouldn't power on. I ended up buying three additional cables because my PSU (ThermalTake Toughpower Grand 1050w RGB Platinum) didn’t provide extra ones. I ordered some 8-pin cables from Corsair, but I didn’t realize I’d mistakenly purchased CPU power cables instead of PCI-e ones. It was late at night, my wife was about to sleep, so I rushed to finish, which made me realize I needed more force than usual to insert the connectors. They initially went in easily until halfway, but the final segment was the toughest.
When I tried to start the PC, it only made a "Click" and wouldn’t power on. The GPU didn’t light up either, leaving nothing visible. The motherboard’s RGB stayed on but didn’t move anything. I then switched to a different 12VRPWR cable (another extension, I’m not sure why), but it also failed to work. Eventually, I decided to power on the PC without any GPU cables connected, which finally triggered a light-up except for the GPU and the motherboard’s DEBUG indicator, which stayed at VGA.
My next attempt (starting to doubt my cable choices) was to connect two of the known PCI-E cables I used for my RTX 3090 just to see if they would react with the new GPU.
🙁
Fortunately, it did light up—but only up to the VGA level, with a faint yellow glow over the "Boot" LED. I think this suggests insufficient power from just two cables. I’m currently at work, so I can’t confirm if anything broke, but I hope my PSU managed to protect the system by not allowing it to start with the CPU cables connected.
I received two new PCI-E cables (confirmed by the label on them) and plan to try them later when I’m home. Fingers crossed.
System Specs:
CPU: Ryzen 7 5800X3D
RAM: Corsair Vengeance 64gb 3600mhz
MOBO: Asus Strix X570-E Gaming Wi-FI II
GPU: Asus Strix RTX 4090 White Edition
SSD: Sabrent Rocket 4TB NMVE
PSU: ThermalTake Toughpower Grand RGB Platinum 1050w
Thank you for your time.
Did you confirm the pin configurations match between Corsair modular power cables and Thermaltake ones on the PSU side? Even with PCIE cables, modular power cables aren't universal. It's likely you risk damaging the GPU, but it probably isn't covered by warranty—though I hope you were lucky.
After reviewing some online documents, it appears the pin layout remains consistent. For now, I can only confirm this later when I return home and test my thermaltake PCI-e cables to ensure the GPU is still functioning properly.
After testing the right cables, everything functioned perfectly. Please verify before you proceed and avoid acting if you encounter similar problems. Don't attempt anything until you have matching cables that suit your power supply, as modern good power supplies usually include strong short circuit protection, increasing the chances of your GPU surviving. In short, check first and only panic if your card is completely damaged. Thank you!