If you are encountering a black screen at the startup of your PC, this may indicate a hardware fault with either the N7 B550 or the hardware installed to it. The N7 B550 has Debug LEDs that indicate what is preventing your PC from passing the POST. POST or the Power On Self Test is how the motherboard checks for any hardware faults. Please reference the photo below for the location of these debug LEDs and other major components.
The debug LEDs are for CPU, DRAM, BOOT, and VGA, this is shown in the photo below:
Before we get into troubleshooting, we always recommend a CMOS clear, as this can resolve some POST issues. The Clear CMOS button is located on the rear I/O and can be used to revert BIOS settings to default.
To clear CMOS, power down your PC, and remove your power cable. Wait 30 seconds to ensure there is no residual power in the PC then press and hold the Clear CMOS button for 3 seconds. If you are still having problems after clearing the CMOS, please refer to the following troubleshooting steps correlating to the debug LED that is lit up on your motherboard
NOTE: If you have an NZXT Prebuilt or Custom Gaming PC, skip the instructions here for the CPU debug LED. Please reach out to our customer service team for assistance.
If you are encountering a CPU debug LED, please try the following:
- Remove your CPU to verify that the CPU pins are undamaged. Damaged Pins and Contacts can look something like this:
- Verify that the CPU is installed correctly with the gold triangle on the CPU pointing to the bottom left of the socket.
- Check that the processor is compatible with the N7 B550 (AMD Gen 2-3)
- Double-check that the CPU power from the PSU is connected properly.
For a DRAM debug LED, please try the following:
- Please remove the RAM and verify that there are no burn marks or chips on the PCB. Then verify the DRAM slots on the motherboard are not bent or coming off of the motherboard.
- Make sure that when the RAM is inserted, it is seated evenly in the DRAM slots. We recommend installing the RAM with the motherboard lying flat on its back.
- Double-check that any dual-channel RAM is installed to the correct slots. Starting from the leftmost slot, the slots are A1, A2, B1, and B2. Your dual sticks of RAM should be installed to A2 and B2.
- Verify that all the RAMs are matching models. Do not mix and match RAM that is not the same model.
- Test your RAM one at a time in each slot on the motherboard. If a particular DRAM slot is not working properly, please contact our Customer Service Team for assistance. If a particular RAM stick prevents the POST, that likely indicates a defect in the RAM.
For a Boot debug LED, the troubleshooting will depend on the type of storage you are using with your system. For M.2 SSDs try the following:
- Verify that the SSD being used is an M.2 NVMe SSD (M-Key). M.2 SATA SSDs (B-Key) are not compatible with the N7 B550.
- Remove the M.2 SSD from the slot to verify the M.2 contacts and the M.2 slot are un-damaged.
- Try switching the M.2 SSD to the other open slot on the board, if this fixes the issue, then please let our Customer Service Team know. If you have two M.2 SSDs and you are getting a BOOT LED, attempt to also try using one M.2 SSD at a time in both slots. If one SSD works in both slots but the other works in no slots, this indicates that one of the M.2 SSDs could be defective.
For SATA based storage from SSDs and HDDs, try the following:
- Please verify that both the SATA data and SATA power cables are connected to your storage device.
- Use a different SATA data and SATA power cable to rule out any defective connections.
- Switch to different SATA ports on the motherboard to verify if a particular port is not functioning properly.
- Find a different SATA storage device to test if other devices work with the motherboard. If other storage devices do work, this would indicate a defect in the storage you were previously attempting to use.
For a VGA debug LED, please try the following:
- Remove your GPU to verify that the card’s PCB is un-damaged and that all contacts are clean on the board. Then verify that the motherboard’s PCIe slot is un-damaged.
- Please try switching the GPU to the other open PCIe slots on the motherboard. If you pass the POST on the other slot, please let our Customer Service Team know, this indicates a defect in the motherboard.
- Try a different GPU, if you get POST on a different card, then the GPU you were using may have a defect in it.
- If using a PCIe riser cable, try testing the GPU directly connected to the motherboard to rule out the riser being defective. Try the previous steps as well.