Ports on the motherboard aren't providing sufficient power.
Ports on the motherboard aren't providing sufficient power.
Hi, I recently noticed an issue with my computer, some ports don't deliver enough power to properly light-up peripherals, don't work or completely shut it. After some troubleshooting, I'm pretty sure that the problem is not related to Windows since it also happens in the Bios and Linux. I've also tried another power supply, cleared CMOS and updated the Bios to the latest version. Here's a picture to illustrate my problem. Green circle works perfectly fine, I can plug both 2.5" HDD and Keyboard and they fully work and light-up Red circle can't power up my keyboard nor my external 2,5" HDD, I can connect my phone or USB sticks but it will randomly disconnect Orange: Can use both port for low powered devices like USB sticks. If I connect the Keyboard the RGB will be dim and if I connect something else to the other port it will disconnect Front 3.0 USB works fine too (no front 2.0 on this computer case) Here's my config: Computer Type: Desktop GPU: GTX 1070Ti 8GB CPU: RYZEN 5 3600 6 CORE 12 THREADS Motherboard: MSI B450 GAMING PLUS MAX BIOS Version: 7B86vHG RAM: 16GB CORSAIR VENGEANCE RGB 3200MHZ PSU: FSP RAIDER S750 750W 80PLUS Silver Case: Phanteks P400A-D
It's quite unusual because the expected power should match the USB standards—USB 2.0 delivers 5V at 500mA (2.5W), while USB 3.2 Gen 1/2 provides up to 20V at 5A (100W).
Ensure the USB ports are configured properly, matching requirements such as charging a phone or other functions.
Never encountered it before, so any USB port should be sufficient for a basic 2.5" external HDD or keyboard, though in my experience it doesn't work. I plan to take out the motherboard from the case when possible to check for shorts or issues with the case or I/O shield.
USB 3.2 typically operates with 5V at type A ports, around 900mA. It seems you might be experiencing a problem where the voltage drops to 4.7V, leading to issues like the external HDD resetting. Verify your power rail voltage and consider checking your motherboard's BIOS settings. Using a multimeter can help confirm the 5V output from your power supply.
Indeed. my case however is different. My USB always seems to have intermittent connection. I troubleshoot my system for quite a time and found out that the 5V rail supply from PSU is 4.74V, which is consider low (I think 5V tolerance is +-5%). I think some USB peripheral will stop working when the voltage is below a certain threshold. I may have some grounding issue, because I just need to probe the 5V and the GND cable from the PSU and the voltage go back up to 4.9V. The symptom OP described sounds similar, so maybe that's what the issue is. To my record, I don't think any of the B450 motherboard support 20V for USB 3.2 gen 2 ports, including USB-C (they do however offer 5V output even when the computer is turned off). I'm not sure where you get your information from, but this is what I get from Wikipedia: https://en.wikipedia.org/wiki/USB At the power section, You can see that USB 3.2 gen 2 output power up to 7.5W (5V, 1.5A). The information you may have obtain could be from USB-C PD (power delivery) system.