You're facing a problem that seems unsolvable to others.
You're facing a problem that seems unsolvable to others.
Hey everyone, I'm just starting out here and came across something tricky. I'm using an ASUS 760 MARS Edition with two GPUs and one of the fans stopped working. The problem is more than just a broken fan—it's tied to the specific design of this card. I ordered a two-fan kit from Amazon, disabled the GPU, and tried connecting the fans again. I learned that ASUS built these cards with 5-pin LST connectors, but now I'm stuck because the pin layout is crucial. I reached out to ASUS support, but they mentioned the pin-out details are confidential. I can't rewire them properly without the correct order, and even trying to swap pins didn't help. A local technician suggested I might need special guidance since the wiring isn't straightforward. I haven't found any official guides or forums discussing this exact issue. My fans are old cooler master models with stickers saying 760 MARS, but I'm not sure how the connectors actually work. Thanks for your help!
Do you still have the original fans? Usually the wires will give you a clear idea of what the connectors do. Are all five pins used? Typically red = 12V, black = ground, yellow = tach, blue = PWM. With a multimeter and scope, you can likely identify the group easily since it connects to all other grounds (such as the PCIe backplate). The 12V might be obvious if it’s linked to the 12V connector pins, but it could also be controlled indirectly. If you have a scope, you can locate the PWM pin.
I’ve never come across a five-pin fan. What function does each pin serve? A quick fix might be sealing the header, taking off the shroud, and attaching standard case fans to the card, then managing them via another system—though that’s more of a haphazard approach than a real solution.
Hello, Yes I still have those old fans. The issue is that one of the newer fans uses just 3 wires while the oru fans require 4. Regarding the video card, I don’t have any experience with it, which is why I’m trying to rewire the fans. I’ll leave two pictures for you. Thanks to the dust, you should be able to tell which ones are older and which are newer.
This seems really interesting. I wasn't able to locate anything on my end. Even the ASUS support mentioned adapters existed, but I couldn't find any. Searching for 5-pin LST headers felt very difficult. I checked EBay too, but there were hardly any results. I'm wondering why... Thanks! I'll also consider purchasing these fans. It looks like only the red and green wires might need a replacement, which would be a simple fix.
The five-pin design on Asus fans serves the same purpose as four-pin fans—they allow each fan to track its own speed independently. Typically, when two four-pin fans are connected, only one uses the third pin for sensing, causing both to report the same speed. To ensure each fan's speed is recorded separately, Asus added an extra sense wire, resulting in a five-pin header. This setup also means each fan has four pins coming from it. Updated August 1, 2022 by IkeaGnome Grammar
Interesting details you shared. It seems the issue might be resolved if we check the wiring setup. A possible solution could be using a 5-pin color code, which often clarifies power distribution. Your intuition makes sense—having at least one side powered would help. Thanks for your patience!
Never attempt this action—there’s a risk you might have accidentally connected 12V to ground or sent current through the PWM sensing line. Avoid forcing connections in various positions; doing so increases the chance of damaging components by routing voltage incorrectly. Using the wrong orientation will likely result in low voltage power and faulty plugs, making it nearly impossible to get a stable connection.
I revisited the pinout details on the OC forums to clarify the situation. It seems they’re using reported speeds from both fans and applying that data to control PWM through a single header for uniform speed. This approach feels unusual compared to the HP HEDT 5 pin design, which typically uses separate RPM headers per fan. In theory, with two fans, someone could verify functionality via the motherboard BIOS if they knew one worked. The diagram shown matches what manufacturers usually adopt. The only logic behind this method appears to be ensuring the second fan follows the correct wiring, colors, and orientation. If you have a multimeter, continuity should exist between pins 1 and 2. I don’t see why pins 3 and 4 would connect elsewhere. Updated August 1, 2022 by IkeaGnome Removed incorrect diagram