When powering on your PSU, no MOBO lights appear.
When powering on your PSU, no MOBO lights appear.
Hey everyone! After assisting my friends with their builds, I’m finally here to tackle this problem myself. When I power on the PSU, nothing lights up on the motherboard, and pressing the power button on my PC (connected to the MOBO) triggers a click or two from the PSU but no action follows. Once I turn off the power and check the board, I spot one pin missing. From the manual it mentions a -5V rail, but I’m unsure if that’s essential since both sides are missing. I checked the CPU fan and pump headers—those seem empty, which contradicts the manual’s advice about airflow. Product photos show others with all pins intact, so I’m worried something might be wrong. I connected the CPU fan header and pump header, but the chassis fan header is blank. I’m trying to confirm if missing these pins is a real issue or just a concern about airflow. Thanks for your help! Components: CPU – Intel i5-12600K, Cooler – Cooler Master ML240L RGB V2, Liquid cooler, MOBO – Asus ROG B660-I, Memory – Corsair Vengeance 32GB DDR5-5600 CL36, Storage – Samsung 980 Pro 2TB m.2-2280, PSU – Cooler Master V850 SFX Gold 850W, Video card – Zotac GeForce RTX 3060 Ti (removed), GPU removal attempt failed).
the pin on the connector is usually absent, as it's common to lose one. you'll notice it missing not only on the connector but also on the motherboard. look for possible shortages on the board itself. contacting metal, dust between connectors, or other obstructions could be the cause. the sound you hear indicates a PSU shortage protection, preventing short circuits in your PC.
It seems the pins are present on the motherboard, but they might not always be in use. I pushed them in and still didn’t get anything working. The cable is labeled "CM-PSU," probably for Coolermaster. I’ve attached photos of all connection points; the one that looks wrong is the MOBO type. It’s proving tough to fully push it down. I also forgot my rubbing alcohol and don’t have a microfiber cloth, so I might try reseating the CPU after tomorrow’s trip to the store.
Use the paperclip method instead of connecting the power supply to the motherboard. Connect the 24-pin plug to the power supply but use a paperclip or wire to touch the PS_On terminal and one ground pin. If the power supply resets itself immediately, it may not be heating up properly. You might need to connect a fan directly to the power supply if it has a MOLEX fan or an adapter. Running 12V power and ground to a 4-pin fan with separate wires will set it to maximum speed.
Great news possibly? It stopped when I connected those two—it produced the same clicking sound as when I attempt to power on the computer. Uncertain if this helps, but I attached a diagram from the MOBO manual and some PSU pin pictures. Just wanted to mention I have an SFX power supply and a Mini ITX MOBO. Not sure if it works, but I'm not sure lol.
It continues performing the click-and-power-off sequence even without any connection to the power source. This suggests the cable or power supply may be faulty and should be returned. The SFX and ITX units adhere to ATX specifications.
You might store the cooler in its original box and keep the motherboard with all its components inside. If not, a safe place works just fine. Keeping it on a shelf is similar to keeping it inside the case. I’m a bit puzzled—what happened to that empty pin housing? Does the picture make sense or are my eyes making a joke? It seems to look damaged and squished.