If any new hardware was recently added to the computer, remove that hardware to make sure it is not causing your issue. If your computer works after removing the new hardware, it can mean a few things. Either the new hardware is not compatible with your computer, a system setting needs to be changed, or the new hardware is defective.

Remove everything from the back of the computer, except the power cable. Turn on the computer and see if it beeps normally. If the computer has never beeped, keep the monitor or display connected to see if any change occurs.

If the computer is not getting enough power or the power is getting interrupted, the computer can encounter problems. Disconnect your power cables from any power strip or UPS (uninterruptible power supply) and connect the computer directly to a known good wall outlet

Loose over time due to heat expansion causes the computer to give an irregular POST. Gently press down on the BIOS chip to make sure it has not become loose

For users who're more comfortable working inside their computer, reseat the CPU by removing it and re-inserting it into the socket. You should also apply a fresh layer of thermal compound between the CPU and the heat sink.

In some situations, a computer may have power related issues often caused by either the power supply or the motherboard. To help determine if this is the issue, try turning the computer on, off, and back on as fast as possible, making sure the computer power light goes on and off. In some situations, you may be able to temporarily get the computer to boot

For users who're more comfortable working inside their computer, reseat the CPU by removing it and re-inserting it into the socket. You should also apply a fresh layer of thermal compound between the CPU and the heat sink.

If the above recommendations still have not resolved the irregular POST, disconnect the riser board (if applicable) and each of the expansion cards. If this fixes 12 the problem or allows the computer to POST, connect one card at a time until you determine which card is causing the problem.

Make sure all fans are running on the computer. If a fan has failed (especially the heat sink fan for the CPU), your computer could be overheating or detecting the fan failure, causing the computer not to boot.