Tip & How-To about Computers & Internet

NO POST / Power General troubleshooting.

This document is intended to help users who are experiencing issues with POST and may have any of the below symptoms.

1. Computer beeps irregularly when the computer is turned on.
2. Computer turns on but does not boot.

Note: Not all computers have beep codes, some of the newer computers have LED's that light up that indicate the error or have a sound file to indicate the error.

A POST failure can be caused by any of the following situations.
1. New hardware conflicting with old hardware
2. Bad or failing hardware device.
3. Other hardware issue. (electrical shorts or incompatibilities.)

Warning: Some of the below steps recommend removing physical parts within the computer. While in the computer it is highly recommend that you be aware of electrostatic discharge and its potential hazards. ALWAYS ground yourself and your equipment. Ensure your computer is unplugged!

Note: Make sure your computer is turning on, if you press the power button and nothing happens (no lights, no sound, no fans, etc.) then this issue is not a NO POST but is an power related issue.

If any new hardware has been recently added to the computer, remove that hardware to make sure it is not the cause of your issue. If after removing the new hardware your computer works it's likely the computer is either not compatible with the new hardware or a system setting needs to be changed to work with the new hardware device.

1. 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 also connect a monitor to the computer to see if any change occurs.

2. Check the stand-offs (the metal or plastic insulators) that keep your motherboard off and away from the case or housing. Ensure they are not grounding or shorting the motherboard out. If they are metal, ensure that the cardboard insulators are present. Ensure the motherboard is not grounding out to the case also at any other point.

3. If you are receiving a sequence of beeps consult your motherboard manual or the motherboard manufacturer's website for a listing of different beep codes and their explanation. These beep codes are meant as a method of quickly identifying what computer component is failing or bad.

4. Check to make sure power cables are not grounding or shorting to the case or other components. Ensure all ends are connected properly, securely, and snugly.

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

6. If you were unable to determine by the beep code what is failing or do not have a beep code disconnect the IDE cables from the CD-ROM, Hard Drive, and Floppy drive from the Motherboard. If this resolves your post failure, attempt to connect each device one at a time to determine which device and or cable is causing the issue.

7. If the above recommendations still have not resolved the irregular POST, start disconnecting your expansion riser cards, these are the cards that are not essential to system operation. Break your motherboard down to the bare basics. Disconnect your floppy drive, CD/DVD ROM, and hard drives Your motherboard basics should have just the following: video card, RAM, motherboard and PSU (power supply unit). If this resolves the issue or allows the computer to post connect one card or device at a time until you determine which card or device is causing the issue.

8. If you continue to receive the same problem with all the above hardware removed attempt to disconnect the CPU and RAM from the Motherboard. Once done insert the CPU and RAM back into the computer to see doing this resolves your issue.

9. Ensure your PSU is of the correct size and power requirements for your system. Many newer motherboards and graphics cards are power intensive. Some newer graphics cards require their own separate power supplies. An underpowered PSU, will also cause system failure. Most new systems will not run well with less than 450W PSUs.

10. If after doing all of the above recommendations you continue to have the same issues unfortunately it is likely that you have bad or incompatible components, in particular RAM. Ensure your RAM is compatible with the motherboard. Many newer motherboards are very specific about what RAM sticks they will accept. Don't mix and match RAM speeds, type, or size.

11. If you have determined your components are compatible, then you have faulty hardware. The next step would be to test each component separately. You will need to find a working motherboard to test RAM with a diagnostic program like Memtest 86+. A faulty motherboard will need to be simply replaced. A bad PSU can only be replaced. Don't attempt to repair a bad or failing PSU. This is quite dangerous. High voltages and hazardous chemicals are present in PSU capacitors and other components – even when main power is disconnected. You can only replace a bad PSU.

12. If you keep getting the same failures after replacing CPUs, motherboards, and PSUs, there is a small chance that one of the peripheral cards is not compatible and causing damage or the card is conflicting with an internal integrated component. If you have integrated video or sound, you need to turn these off before using external cards.

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1 Answer

any help for beeping acer laptop when opening..thanks


g'day!

i would like to know how many and the kinds of beeps? there are what they call beep codes which indicates what kind of problem the your laptop is experiencing: here are the common ones:

0 beep = no power, loose card, short
1 short beep = normal,POST (Power On Self Test), your computer is ok
2 short beeps = POST error, review screen for error code.
continuous beeps = no power, loose card, short
repeating short beeps = no power, loose card, short
1 long, 1 short beeps = motherboard issue
1 long, 2 short beeps = video issue
1 long, 3 short beeps = video display circuitry
three long beeps = keyboard/keyboard card error
one beep, blank, incorrect display = video display circuitry

aside from the 1 short beeps, you need to take your laptop to a technician to have it looked at.

cheers mate!
jelo a.

Aug 21, 2011 | Computers & Internet

3 Answers

computer turns on and 3 beeps happen


ReSeat the ram. If there's 2 sticks, remove 1 of them, and try it, then try with just the other.
Clean the RAM contacts while they are out.

Feb 28, 2011 | Computers & Internet

1 Answer

no display


This issue can be caused by any of the below possibilities.

  1. Monitor is not on
  2. Computer is asleep
  3. Connections not connected properly.
  4. Monitor settings are not correct.
  5. No Post.
  6. Hardware issue.
Solution: The following is monitor troubleshooting. If your monitor receives a proper display until it gets into Windows 3.x, Windows 95, Windows 98, Windows NT, Windows 2000, Windows ME, or Windows XP please refer to document CH000192.

Monitor is not on

Make sure the monitor is on. If no power light (green or orange light) is seen on the monitor display try pressing the power button until it comes on. If no light comes on after several attempts continue to below connections not connected properly.

Computer is asleep

If your computer monitor was on and you stepped away from the computer and upon returning it was black it's likely that the computer is asleep. Try moving your mouse, clicking the mouse buttons, and/or pressing any key (space bar) on the keyboard to wake it up.

Connections not connected properly

vga.jpgMake sure that you are connecting the monitor to the back of the computer in the 15-pin connector as shown to the right or older computer 9-pin connection.

If the computer is properly plugged in, make sure it's getting getting power.

If you are not receiving power from a known working wall outlet and if the power cord is removable, replace it with the one connected to the computer and attempt to power on the monitor again. If the monitor still does not get power or it is not removable, it is recommended that the monitor be replaced or serviced at a local TV / Computer repair shop.

If the monitor is receiving power, check the status light.

If the light is orange or flashing ensure that the monitor is not in a suspend mode by moving the mouse or pressing a key on the keyboard. If the computer does not get a display by moving the mouse or touching the keyboard, turn off the computer and monitor and reconnect the data cable from the back of the computer, and if removable, the back of the monitor. Turn the computer back on; if you still encounter the same issue, continue reading through the other possibilities.

Monitor settings are not correct

Ensure that the brightness and contrast is turned up or attempt to adjust the brightness and contrast. If adjusting the brightness or contrast has no affect on the monitor continue reading through the other possibilities.

No Post

Does the computer beep when it is powered on and/or does it appear that the computer has activity? If the computer does not beep or beeps abnormally it is possible that the computer itself is experiencing a hardware issue or is exhibiting a No Post.

Steps on troubleshooting an irregular POST or no beeps can be found on document CH000607.

Hardware Issue

If you have followed the above recommendations and are still encountering the same issue, it is likely that the computer may have either a bad video card or monitor. The best method of determining this is to do one or both of the following

  • Disconnect your monitor and attempt to connect it to another computer. This can be a friend or family's computer and/or it can be taken to a service center.
  • Borrow a computer monitor and connect it to your computer. This will not harm the other computer monitor in any way.

If your monitor works on another computer it is safe to assume that the video card or potentially the motherboard within the computer is bad. Steps in troubleshooting a video card can be found on document CH001028.

Nov 26, 2010 | ASUS P4S333 Motherboard

1 Answer

my gateway g7-500 fails to start properly. Whemn power on I get a long beep followed by 2 short ones and the monitor screen remains black.


Cause:This issue can be caused by any of the below situations.
  1. New hardware conflicting with old hardware.
  2. Bad or failing hardware device.
  3. Connections not connected or connected properly.
  4. Recent electrical storm that caused a surge that damaged computer.
  5. Other hardware issue.
Answer:Warning: Some of the below steps recommend removing physical parts within the computer. While in the computer it is highly recommend that you be aware of ESD and its potential hazards. Information about ESD and proper grounding techniques are found on our ESD help page.
Note: Make sure your computer is turning on, if you press the power button and nothing happens (no lights, no sound, no fans, etc.) then this issue is not a NO POST but is an power related issue see document CH000312.
Remove new hardware If any new hardware has been recently added to the computer, remove that hardware to make sure it is not the cause of your issue. If after removing the new hardware your computer works it's likely the computer is either not compatible with the new hardware or a system setting needs to be changed to work with the new hardware device.
Disconnect external devices 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.
Identify beep code If you are receiving a sequence of beeps see our beep code page for a listing of different beep codes and their explanation and/or your motherboard or computer documentation. These beep codes are meant as a method of quickly identifying what computer component is failing or bad.
Check all fans Make sure all fans are running in the computer. If a fan has failed (especially the heat sink fan for the CPU) your computer could be overheating and/or detecting the fan failure causing the computer not to boot.
Check all cables Verify that all the cables are properly connected at that there are no loose cables by firmly pressing in each cable.
  • All disk drives should have a data cable and power cable connected to them.
  • Your power supply should have at least one cable going to the motherboard. Many motherboards may also have additional cables connected to them to supply power to the fans.
Disconnect all expansion cards If the above recommendations still have not resolved the irregular POST attempt to disconnect the Riser board (if applicable) and/or each of the expansion cards. If this resolves the issue or allows the computer to post connect one card at a time until you determine which 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 the IDE, SATA, SCSI, or other data cables from the CD-ROM, hard drive, and floppy drive from the Motherboard.
If this resolves your irregular post or you now get an error message attempt to re-connect each device one at a time to determine which device and or cable is causing the issue. In some situations it can also be simply 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 attempt to 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.
  1. Re-insert the memory into the same slot.
  2. If you have more than one stick of memory remove all but one stick of memory, try rotating through each stick.
  3. 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 which 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 and/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 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, and/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 bad Motherboard, CPU, and or RAM. The next step would be either to replace these components and/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 and/or try swappable parts from other computers.
  • See our buying help page for tips and information about buying computer hardware.
  • See document CHADD for additional information about installing new hardware into the computer.

Nov 29, 2008 | Computers & Internet

1 Answer

RD480-1939 2 post beeps


This document is intended to help users who are experiencing issues with the POST and may have any of the below symptoms.
  1. Computer beeps irregularly when the computer is turned on.
  2. Computer turns on but does not boot.
Note: Not all computers have beep codes, some of the newer computers have LED's that light up that indicate the error or have a sound file to indicate the error.
Cause: This issue can be caused by any of the below situations.
  1. New hardware conflicting with old hardware.
  2. Bad or failing hardware device.
  3. Connections not connected or connected properly.
  4. Recent electrical storm that caused a surge that damaged computer.
  5. Other hardware issue.
Answer: Warning: Some of the below steps recommend removing physical parts within the computer. While in the computer it is highly recommend that you be aware of ESD and its potential hazards. Information about ESD and proper grounding techniques are found on our ESD help page. Note: Make sure your computer is turning on, if you press the power button and nothing happens (no lights, no sound, no fans, etc.) then this issue is not a NO POST but is an power related issue see document CH000312. Remove new hardware If any new hardware has been recently added to the computer, remove that hardware to make sure it is not the cause of your issue. If after removing the new hardware your computer works it's likely the computer is either not compatible with the new hardware or a system setting needs to be changed to work with the new hardware device.
Disconnect external devices 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.
Identify beep code If you are receiving a sequence of beeps see our beep code page for a listing of different beep codes and their explanation and/or your motherboard or computer documentation. These beep codes are meant as a method of quickly identifying what computer component is failing or bad.
Check all fans Make sure all fans are running in the computer. If a fan has failed (especially the heat sink fan for the CPU) your computer could be overheating and/or detecting the fan failure causing the computer not to boot.
Check all cables Verify that all the cables are properly connected at that there are no loose cables by firmly pressing in each cable.
  • All disk drives should have a data cable and power cable connected to them.
  • Your power supply should have at least one cable going to the motherboard. Many motherboards may also have additional cables connected to them to supply power to the fans.
Disconnect all expansion cards If the above recommendations still have not resolved the irregular POST attempt to disconnect the Riser board (if applicable) and/or each of the expansion cards. If this resolves the issue or allows the computer to post connect one card at a time until you determine which 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 the IDE, SATA, SCSI, or other data cables from the CD-ROM, hard drive, and floppy drive from the Motherboard.
If this resolves your irregular post or you now get an error message attempt to re-connect each device one at a time to determine which device and or cable is causing the issue. In some situations it can also be simply 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 attempt to 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.
  1. Re-insert the memory into the same slot.
  2. If you have more than one stick of memory remove all but one stick of memory, try rotating through each stick.
  3. 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 which 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 and/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 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, and/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 bad Motherboard, CPU, and or RAM. The next step would be either to replace these components and/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 and/or try swappable parts from other computers.

Nov 21, 2007 | EliteGroup (ECS 915PL-A2) Motherboard

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