WARNING: Before you start troubleshooting remember that you are dealing with electricity that can KILL.
http://www.kitchentablecomputers.com/static.php - rules Make sure that your RAM modules and Cmos battery are securely seated on some motherboards Cmos batteries are soldered in. Open computer and reseat memory Sometimes when the computer is moved or over time a memory stick can become loose causing the computer to be unable to read the memory or get errors as it's reading it. Disconnect all expansion cards If the above recommendations still have not resolved the irregular POST, disconnect the riser board(if applicable) and each of theexpansion cards. If this resolves the issue or allows the computer to POST connect one card at a time until you determine what card is causing the issue. Disconnect all drives If you were unable to determine by the beep code what is failing or do not have a beep code disconnect theIDE, SATA, SCSI, or other data cables from theCD-ROM, Hard Drive, and floppy drive from theMotherboard. If this resolves your irregular POST or generates error messages re-connect each device until you determine what device or cable is causing the issue. In some situations it can also be a loose cable connection that causes the issue. Remove the RAM If you continue to to receive the same problem with all the above hardware removed, disconnect the RAM from the Motherboard and turn on the computer. If the computer has a different beep code or if your computer was not beeping and is now beeping turn off your computer and try the below suggestions. ' Making sure to turn off the computer each time you're adding and removing the memory and then turning the computer back on to see if the suggestion resolves the issue. Re-insert the memory into the same slot. If you have more than one stick of memory remove all but one stick of memory, try rotating through each stick. Try one stick of memory in each slot. If you're able to get the computer to boot with one or more of the sticks of memory it's likely you're dealing with some bad memory. Try to identify what stick of memory is bad and replace it. If you're able to get memory to work in one slot but not another slot. You're motherboard is defective you can either workaround the issue by running the memory in a different slot or replace the motherboard. Power cycle the computer 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 cause of your issue try turning the computer on, off, and back on as fast as possible, making sure the computer power light goes on and off each time. In some situations you may be able to temporarily get the computer to boot. This should only be used as a temporary workaround if you're able to get this to work. Often this is good for users who may have not done a backup and need to get the computer up one more time to copy files before starting to replace hardware. Disconnect and reconnect the CPU (central processing unit) For users who are more comfortable working with the inside of their computer or who have built their computer one last recommendation before assuming hardware is bad is to reseat the CPU by removing it and putting it back into the computer. Bad motherboard, CPU, RAM, or power supply If after doing all of the above recommendations you continue to have the same issue unfortunately it is likely that you have badMotherboard , PSU ( power supply unit ), CPU, or RAM. The next step would be either to replace these components or have the computer serviced. If you plan on doing the repairs yourself or you are a repair shop it is suggested that you replace the Motherboard first, RAM, CPU, and then power supply in that order or try swappable parts from other computers.