How to troubleshoot a mining rig that won't start?

If your mining rig won’t start, begin by checking the PSU with a multimeter, inspecting connections, and testing with a known-good unit.

Jul 15, 2025 at 10:49 am

Checking the Power Supply Unit (PSU)

When a mining rig fails to start, the power supply unit (PSU) is often the first component to investigate. Begin by verifying that the PSU is properly connected to a functional power outlet. Use a different device to test the outlet and ensure it's delivering electricity. Next, inspect the power cable for any visible damage or fraying.

Use a multimeter to test if the PSU is outputting the correct voltage. If you don't have one, consider borrowing or purchasing an affordable digital multimeter. Set it to measure DC voltage and check key rails like the 12V, 5V, and 3.3V lines. Any significant deviation from these values may indicate a faulty PSU.

If possible, swap the PSU with another known working unit to confirm whether this resolves the issue. This step can be especially useful if you're uncertain about your testing methods or tools.

• Ensure all internal connections are secure
• Verify the PSU switch is turned on
• Check for blown fuses inside the PSU

Examining the Motherboard and BIOS

The motherboard serves as the central hub of your mining rig. A malfunctioning motherboard can prevent the system from booting entirely. Start by visually inspecting the board for bulging capacitors, burn marks, or other signs of physical damage.

Clearing the CMOS might resolve issues related to corrupted BIOS settings. You can do this by locating the CMOS jumper on the motherboard and moving it to the clear position, or by removing the CMOS battery for a few minutes before reinserting it.

If the motherboard has onboard LEDs for diagnostics, refer to its manual to interpret any error codes displayed. These codes can help identify specific problems such as memory or CPU initialization failures.

• Ensure all RAM modules are seated correctly
• Disconnect unnecessary peripherals to simplify troubleshooting
• Try using a minimal setup (CPU, one stick of RAM, and GPU) to isolate the problem

Verifying GPU Connections and Functionality

Mining rigs typically rely on multiple GPUs, which are essential for their computational tasks. If even one GPU is improperly connected or defective, it could prevent the entire system from starting.

Begin by checking all PCIe power cables connected to each GPU. Ensure they are firmly plugged into both the PSU and the graphics cards. Also, verify that the GPUs are properly seated in their PCIe slots on the motherboard.

Remove all but one GPU and attempt to start the rig with just that single card. If the system boots, gradually add back the remaining GPUs to identify any problematic ones. This method helps pinpoint whether a specific card is causing the issue.

• Test each GPU individually in another system if possible
• Inspect for bent pins or damaged connectors on both the GPU and motherboard
• Ensure the riser cables are fully inserted and functioning properly

Investigating Riser Cables and Expansion Risers

Riser cables are critical components in multi-GPU mining rigs. They connect the GPUs to the motherboard via PCIe slots and allow for better airflow and space management. Faulty risers can cause the rig to fail at startup.

Start by checking each riser cable for loose connections. Ensure that both ends—connecting to the GPU and the motherboard—are securely fastened. If a particular riser seems suspect, try replacing it with a known working one.

Power down the rig completely before swapping risers. Test each GPU using a different riser to see if the issue follows the cable or remains with the GPU itself. Some risers may not provide enough signal integrity, leading to boot failures or intermittent operation.

• Use USB 3.0 risers for better compatibility
• Avoid mixing different types of risers unless confirmed compatible
• Ensure the motherboard supports multiple GPUs and PCIe bifurcation if applicable

Reviewing Software and Boot Configuration

Even if the hardware appears functional, software misconfigurations can prevent a mining rig from starting correctly. This includes the operating system, mining software, or BIOS settings.

Check whether the bootable USB drive or SSD is properly connected. Sometimes, a loose connection can prevent the system from detecting the boot device. Try inserting it into a different USB port or SATA slot.

Reinstall or update the BIOS firmware if necessary. Manufacturers occasionally release updates that fix compatibility issues with newer hardware or software. Follow the motherboard manual closely when flashing the BIOS to avoid bricking the board.

If you're using a mining-specific OS like HiveOS or EthOS, verify that the configuration files are correct and that the mining script runs without errors. Incorrect parameters or missing dependencies can halt the startup process.

• Confirm that the mining OS image was written correctly to the storage device
• Check for any typos in the mining configuration files
• Ensure drivers for the GPUs are installed and up to date

Frequently Asked Questions

Q: Why does my mining rig turn on briefly and then shut off?

A: This behavior may indicate a power delivery issue. Check the PSU wattage and ensure it meets the total power requirements of all components. Also, verify that no short circuits exist between the case and motherboard.

Q: Can overheating prevent a mining rig from starting?

A: While overheating usually causes shutdowns after startup, extreme thermal conditions might interfere with initial booting. Ensure proper ventilation and clean dust buildup from fans and heatsinks.

Q: How do I know if a GPU is dead?

A: Test the GPU in another system or use diagnostic tools like GPU-Z to monitor temperatures and voltages. If the card doesn’t display any output or registers errors consistently, it may be faulty.

Q: Is it safe to use low-cost PSUs for mining rigs?

A: Using substandard PSUs can lead to instability and hardware damage. Always opt for reputable brands with sufficient wattage and 80+ certification to ensure reliable power delivery.