Getting everything assembled for the first time and discovering a boot error (or just that the system doesn’t even “try” to turn on) can be disheartening, but most first-time boot issues are easily resolved with a set of basic troubleshooting steps. We’ll offer those here.
The good news is that most first-boot issues are relegated to power and cable management (and the connection of those cables) or to BIOS settings conflicts and general “unhappiness” of the CMOS battery. Although it is always possible that static electricity damaged a component, it is not common when following our earlier-defined outlines for preventing ESD. DOAs are also possible, but not all that common.
If your system is freshly built and exhibits one of these symptoms, then use this Basic Troubleshooting Steps outline to resolve issues early:
- System “clicks” on, fans try to spin or spin very briefly, and then powers itself off nearly immediately.
- System completely fails to boot. No power on, no LEDs on the board are active.
Basic PC Troubleshooting Outline
This outline is detailed in individual paragraphs below:
- Check that the PSU is switched to ‘1’ (on) and plugged into the wall – yes, really.
- Double-check that the outlet is good (or try another).
- Check all power connections (PSU-side and board-side).
- Reseat memory and VGA.
- Reset / clear CMOS.
The below sections will walk through each of these individual steps. If these steps don’t sound quite right for your issue – or you’ve exhausted them and need more in-depth testing – our next troubleshooting guide will cover part swapping and issue or defect analysis.
We’re just ruling out the obvious with this one. Make sure that the power supply is connected to the wall with an appropriate power cable. Most PSUs use a standard power cable, but some high-wattage supplies (like the NZXT Hale v2) will use 10A cables. Use the cable that was provided with the PSU for assurance.
Flip the PSU switch to the correct ‘1’ (on) position. If it’s already there, toggle off, wait a few seconds, then back on. You will sometimes hear a ‘click’ that lets you know the components are active.
If it’s still no good, just to make sure we eliminate easiest tests first, try a different power outlet. If the power of the system is excessive – like in multi-GPU computers – you could blow a breaker by exceeding the standard US ~1500W supply. Testing high-wattage PCs on a separate circuit from other high-wattage PCs is encouraged.
Power Connection Checklist
Follow this checklist for power connectivity. Note that data cables, like SATA or U.2, and even GPU power cables are not necessary to get the system simply to boot. You’ll obviously want the cables for the video card connected, but the absence thereof will not prevent a boot (screen will display a warning to connect PCI-e power cables).
- 24-pin power located near RAM. Ensure that the clip lines-up with the clip on the socket. There is generally only one way to plug these headers in, but a builder could force a backwards connection with enough force (part of our “if it doesn’t go in easily, stop” rule).
- 4/8-pin power near the CPU. This is the EPS 12V supply and is required for boot and CPU power; in our experience, it is also the most commonly overlooked. Almost all motherboards use 8-pin headers for this. Some ultra-budget, mainstream-targeted boards will use 4-pin headers. High-end OC boards occasionally offer optional, additional sockets (upwards of 16 pins) for high overclocks. At this point in the process, you’ve not booted yet and therefore have no overclock – these are not necessary unless the board dictates their connection.
- VGA power connectors for the video card.
- SATA, U.2, and data cables are not needed, but may as well be plugged-in at this point. We will ditch them if we have to go barebones (later in the process).
- PWR_SW connector for the case to the motherboard (this is what makes the power button work).
Next, check that all headers for all cables connected to and fully seated within any modular receptacles on the power supply. You an apply a little bit of force here, just make sure it’s seated in the correct orientation and that the clips are socketed.
Attempt a boot.
If it’s still no good, let’s try the next part:
Jump-Start with a Screwdriver
Just to rule-out the possibility that the PWR_SW cable is damaged or defective, we can easily jump-start the system by bridging the PWR_SW contacts through a screwdriver. This is trivial and a useful skill to have.
- Disconnect PWR_SW connector from the motherboard.
- Using a screwdriver, bridge the PWR_SW pins on the motherboard. This is done by using a fat enough screwdriver that the metal tip forms a physical “bridge” between the pins, through which electricity will flow.
- Remove the screwdriver immediately after start.
- The system should power-on if all is well.
Reseat Memory & VGA
If there’s still no video or a failed POST (power-on self-test), it’s worth checking memory and video card seating. If installed improperly or not fully seated (or oxidized from a lack of use over a long period of time), reseating the RAM and VGA is a useful troubleshooting tactic.
To do this, simply remove and reinstall each device per our earlier instruction. Make sure an audible ‘click’ is emitted once the memory clamps and PCI-e clamp lock into the devices. Avoid re-installing the CPU at this time. That is almost never the issue (as long as it was installed properly to begin with) and is the most difficult to re-mount.
Clear CMOS Battery
All of the motherboard’s configurable UEFI or BIOS information is stored on the CMOS battery, a round, silver battery that’s normally positioned near between PCI-e slots (on an ATX board) or near the video card. Some mini-ITX boards will mount the CMOS battery vertically to save space.
It is possible – and has happened to us regularly – that settings in BIOS are somehow preventing a proper boot. This is the nature of introducing the motherboard to a new CPU and memory. To reset CMOS, the most sure-fire way is to follow these steps:
- Disconnect power from the PSU (to the wall).
- Toggle the PSU off.
- Locate CMOS battery. Depress the tab and pop the battery out.
- Wait 15-30 seconds, then re-insert battery.
- Reconnect power (and VGA, if it was in the way) and toggle PSU on.
- Attempt a boot.
That will solve any firmware-related issues. If that’s no good, it’s time to move on to more advanced troubleshooting steps. – Steve Burke, GamersNexus