Only certain power supplies are compatible with this motherboard.
Only certain power supplies are compatible with this motherboard.
I used an Asus P7P55D-E LGA 1156 board with an i7-870 CPU. It runs only on a Corsair RM850 power supply, and I can boot into Windows successfully. Two other supplies—Ryzen System (CM Silent Pro 600W) and Corsair VS450—are working fine. When I connect them, the fans spin repeatedly. What might be causing this issue?
This scenario involves closely examining the power supply connectors, checking for dirt, corrosion, or bent parts using a magnifying glass. If nothing stands out, I’d test the machine with a killawatt meter to measure its power draw. This could relate to how the PSUs are built, but that’s outside my expertise. Someone else should handle that. Edited September 8, 2022 by Bombastinator
I'm familiar with this older era of MBOs, though I've only worked with single rail PSUs and never faced problems. My current setup uses a 1600W T2 unit that handles whatever it needs. Then there was a newer multirail model (1000W RMi) which is a higher-end design—maybe it struggles with older hardware requirements. I'm not sure if newer PSU designs are compatible with how past components operated. Motherboards seem to prefer straight 12V power, so it's likely the issue lies in the power delivery rather than the board itself.
If there are no issues in the connectors, it might be that the device is drawing more than the other power supplies can handle. That’s unusual for a 650 unit. The total wattage of these PSUs is usually 3.5, 5, and 12V combined. Also, the 12V output is sometimes divided, which explains why people mention rails. I thought about placing it on a kill switch.
I've linked the GTX 1650 to this setup but it doesn't start up even when using another graphics card. Below are the full specifications of the machine that won't boot with the two PSU i7 870 (LGA 1156) Asus P7P55D ELX motherboard coolers and CM Hyper 212 4 x 4GB Corsair DDR3 RAM SSD. The system uses Samsung 860 Evo 250GB GPU and Gigabyte GTX 1650. PSU1 is Corsair RM850, it boots correctly. PSU2 is Corsair VS450, it loops without a post or fan spin. PSU3 is Cooler Master CM600 Silent Pro, it also loops similarly. Please note that PSU2 and PSU3 function properly with other Ryzen 2700x and 1600x systems, including the GTX 1660 Super.
It includes an integrated graphics chip. It’s not ideal but it functions adequately for displaying images. If you take out the dedicated GPU completely, connect your monitor directly to the motherboard and power it up, you can still see something.
It lacks an IGPU, so the Lynnfield CPU is used instead, and this specific i7 model comes without built-in graphics.
It seems the issue isn’t here. Likely the server hardware is the problem. It’s an old component. The motherboard might have given in. Check for swollen capacitors or obvious corrosion. Two main chances: either the other two power supplies lack sufficient voltage, or there’s a faulty port or connection that the 850 ignores while the 650 does.