Troubleshoot No Post
Use the steps below to troubleshoot a no post or no power situation. (follow these steps in order. some steps may or may not apply to your system or situation. Just skip the steps that don't apply)
- Unplug and plug the power cord back in. If the system comes on, your done. If not continue
- Did you add any hardware about the time this problem began? If so, try removing the hardware.
- Was the system hit by lightening? Click here for information about lightening strikes and computers.
- Computer will not come on - After system been off for awhile, it will not work
- Does the power button light up? if it does what color is it? Does it blink or steady? Check the computer manual. Some systems have the power button blink or a different color to indicate various issues. Same applies to the next step as well.
- Some systems have LED lights in the back. Is any of them lit?
- Are you getting any beeps? Check the computer manual for the beeps. Different beeps indicate different issues.
- If the system comes on but will not get passed POST, are you getting any error messages?
- Is there any frayed wires?
- Try another wall outlet. (even if you are getting power, you may not be getting enough power from the outlet)
- Bypass any surge protectors.
- Disconnect all cables except for the power cord.
- Some power supplies have a voltage selector to switch from 115 to 230. Check to make sure the voltage is set to 115 (usually located near where you plug the power cord into)
- Flip the voltage selector from 115 to 230 and then flip it back to 115. (Make sure the power cord is disconnected and you push the power button for five seconds to drain power before doing this step)
- Try a different power cord.
- Disconnect power cord
- Remove all PCI cards (such as modems, sound cards, network cards so forth)
- Disconnect power to All IDE or SATA drives (such as CD-ROM, Hard drive, zip)
- Disconnect power to the floppy drive
- Disconnect Data cable that goes to the hard drive or CD-ROM drive.
- Remove memory.
- If your system has an RTC Jumper, you can try resetting it. (This sometimes can harm the system. Use with care)
- Reseat the power connector from the power supply to the motherboard (it will have 20 colors)
- Try the memory in a different slot.
- If you have more than one stick of memory, try one stick at a time in all slots.
- Remove any video cards you have on the system. (You might have an onboard video or both onboard and a video card. If you do, try the onboard video)
- Plug just the power cord in.
- Do you get a light on the motherboard? (not all motherboards have this feature)
- What color is the power button? Is it flashing? Is it the same color as before troubleshooting or different? (some systems don't have this feature. It may light up but not change)
- If your system has LEDs for troubleshooting, are they different then when you first started?
- Does the fan on the power supply spin?
- Take a look at the motherboard and see if you see any swollen or leaking capacitors. Click here for more information.
- Does the power supply seem hot (where you plug the power cord in and see if it is hot to touch. (Be careful, if the power supply is failing, it can be real hot and can burn you if you are not careful. It should be warm but not hot. Also do not stick any object into the fan. This can cause injury.)
- Does the system fan spin? (it may not always spin, depends if the system thinks the system needs it and depends on the system features)
- Is the processor and heat sink seated properly? (The processor or heat sink may need to be reseated. However, unless you know what you are doing, this can cause more issues. If you decide to reseat the heatsink and processor, use caution)
Your system may not have LED lights on your system, but your system will have beep codes and most motherboards have a light on it to let you know there is power to the board. Most systems will also have lights on the front of the system and probably on the power button. You will need to check the manufacturer.
There is numerous possibilities when you have either a no POST or a No Power situation.
- The light on the motherboard indicates the board is getting power. This can indicate the power supply is OK. This is not always the case. The power supply can still be the cause.
- If your getting beeps then chances are the power supply is OK. The beeps probably indicate a problem elsewhere, but with computers nothing is definite.
- There is different beeps and you will have to check the manufacturer of your motherboard for what the beeps indicate. The two most common beeps are for memory or video. (usually memory). You may get a beep that doesn't go along with the manual. This may be due to the system having more than one issue and confused on how to respond.
- When there is beeps, this can be caused by the processor, motherboard, or a device that is or was connected to the system. For example, if you was getting memory beeps with everything connected, and you are still getting memory beeps after removing all the devices, It can be the memory, motherboard, or processor.
- If you get life with the memory in a different slot, then the problem is probably the motherboard.
- If you get life with only one stick of memory but not with the other, then it is bad memory.
- If you get life with only one stick of memory (doesn't matter which stick) but not with both inserted, then it is probably bad motherboard.
- A PCI card such as modem, sound card and so forth can go bad and cause the system to not post. If the system comes on with them out, try putting them back in one at a time till the problem comes back.
- You could have a loose connection and reseating cards and cables may fix the issue.
- The issue you are having can be an intermittent issue and you might get it to work for awhile but the problem returns.
- If the issue was caused by a storm, power failure, or improper connection of devices, numerous items can be damaged. Some items may still work but have been weakened and fail later. Click here for information on storm, surge or power failure issues.
- Some systems have their power button flash or go amber depending on the issue you are having. You will need to check the manufacturer for this information.
If you have another system with the same parts, you can try parts of that system on this system to see if you can narrow down the cause. One word of caution... If the part has a short, there is always a possibility that part can damage another system, so if you decide to try the part in another system, you do stand a chance of damaging another system. Unfortunately this is a judgment call you will have to make.
This is only a guide on the steps on how to troubleshoot a system with a no post or no power. There is too many possible causes to determine what the issue is using this troubleshooter. After you use this troubleshooter, consult the manufacturer of the system for further information on what the cause is.
If a part is shorted, it can damage other parts as well. After stripping system down, reinstall one piece at a time till the problem comes back. For example lets say the modem is shorted, but you don't know that. You strip the system and determined the motherboard is bad so you buy and install another motherboard. You put all parts back in the system and now the system is dead again. You strip the system and find out the new motherboard is bad. You now know something else is killing it but since you put everything in at one time, you don't know what part it is.
When you reinstall the parts install the required parts (motherboard, CPU, and power) if you are getting the correct indications that it is working, then install one stick of memory. If that works then keep installing pieces one at a time till all parts are installed and system is working or when the problem returns. If you did it this way and the modem takes the system out, you will know it was the modem because that would be the last part you installed.