The goal of this content is to quickly guide new system builders through common build problems with as little complexity as possible. We may explore longer, issue-dependent pieces in the future, but this guide is meant to be kept as simple as possible.
Common PC build errors and startup issues will be resolved by the step-by-step troubleshooting guide below. Common issues we review include:
- No display on startup (no input detected), even if the fans are running
- Fans spin then instantly stop (turn off)
- The system does not start
- The system beeps several times during startup or displays error codes on the seven-segment display
- Power “clicks”, but the computer does not turn on
- Go “down to the basics” for troubleshooting and testing
Between Patrick Stone, GN Hardware editor, and myself, we’ve built hundreds of computers and laptops over the last decade or more. In this quick video, we talk about the most basic troubleshooting tactics that fix an overwhelming majority of startup issues. The rest is shown below.
How to Troubleshoot a New PC That Won’t Turn On
One thing we don’t mention in the video is what to do once a point of failure is found. A somewhat terrifying amount of components arrive DOA, so although user error is often a significant cause of boot failure, identifying a device as the root cause ultimately requires that device to be replaced. If it’s a new release, you probably still have less than 30 days of return with sites like Newegg and Amazon, which will help you out at no cost (and if there’s a restocking fee for your broken product, we recommend that you call and speak – calmly and politely – to an agent; we’ve never had to pay for a return label or restock DOA components). If it is not new, you have to go through the warranty channels (RMA) or simply buy a new component from your pocket.
Use a PC speaker or seven-segment display
This is overlooked by most builders. Although not as common these days, some cases and motherboards still include something called “PC speaker” or “SPK” on most motherboards. This device – a small speaker attached to a 4-pin header – emits POST (power-on self-test) beep codes. If all is well, a single beep will sound from the speaker. If an identifiable RAM or video problem is detected, the PC speaker may emit a beep code (a combination of long/short beeps) for user decoding. Beep codes are often defined in manuals, but can also be found on vendor BIOS websites (AMI, Phoenix, etc.).
Alternatively, a more simplified diagnostic method would include a seven-segment display, named because it uses seven line segments to create hexadecimal and alphanumeric output. These are found on most mid-range or higher boards, and are often a good reason to choose a higher-end board.
This will guide you directly to the problem, at which point component-specific troubleshooting can begin.
Quick Troubleshooting Steps
These steps solve 90% of the problems we encounter. Looked:
- Verify that all power cables are properly connected to the three main locations: (1) 8-pin or 4-pin header, located near the CPU; this is often omitted; (2) 24-pin header on right side of board; (3) GPU power cables. Disconnect and reinstall these headers, make sure full contact is made between the pins and neither side is skewed.
- Reinstall the RAM. RAM can often be the cause of “no display” issues. Just because no display is outputting doesn’t mean the video card is faulty; there may be something earlier in the boot pipe that is preventing going to video, and that’s normally RAM.
- Reseat the video card.
- Clear the CMOS battery. To do this, unplug the system power, then remove the silver battery for about 15-30 seconds (or use the CLR CMOS switch).
If this does not solve the problem, then we suggest that you go back to basics. This is done by removing all non-essential components. Essential components include:
- Power source
- 1x RAM stick
If your processor does not have an IGP present (the motherboard does not have an onboard output), you will need to include a video card in this list.
Test again. Swap RAM sticks until they have all been independently validated.
Still no luck?
If there’s still no luck, it’s time to start digging deeper into the problem. It’s at this point that it’s useful to have another system – perhaps your old system or a friend’s – to troubleshoot the new one. We recommend removing the parts that seem to be related to the problem, placing them in the non-working system, and looking for the dead component. RAM is normally the go-to given its ease of access, but the PSU would probably need to be swapped out at some point.
Of course, there is always our comments section (below!) or our forums, for direct and individual support for PC boot problems.
-Steve “Lelldorianx” Burke.