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mother board no beep
- Thread starter benzhaotb
- Start date
ski
Technical User
- Oct 11, 2000
- 2,467
Check the CMOS battery for the correct voltage(3V).
If that's ok, then clear CMOS by either removing the CMOS battery, or with a MB jumper(see your MB's documentation for the proper jumper).
If no luck, then connect only the power supply, MB, CPU, video card, memory, case speaker and power button, and monitor, make sure the power supply's voltage selector switch is set to the correct voltage, the PS connection to the MB as well as all cards and the memory are all firmly seated(sometimes a hard push is required to seat them properly), and place the MB on a piece of cardboard.
If the system starts up and there's a display with the MB on cardboard, but things fail to work when the MB is connected to the case, then check for a grounding problem with the MB(usually a metal standoff contacting a MB printed circuit or component).
(A)MB Has LED's:
(1)If the MB standby LED does not light up when you turn on the power supply's switch, then slightly raise the PS main power connector out of the MB connector a little. If the MB LED lights up, then either the PS or the MB connector is bad.
(2)If the MB standby LED does not light up by doing the above, then test the PS by keeping it connected to the MB and jumpering the green wire with any black wire on the back of the PS connector. If the PS's fan does not run, then either the PS, AC power cable, AC power cable connector, surge arrestor, or wall outlet is bad.
(3)If the PS fan runs, then check the following with a voltmeter with the fan running:
yellow wire and a black wire- +12V
red " " " " - +5V
orange " " " " - +3.3V
If these voltages are not up to spec, then the PS is bad.
(4)If the PS fan runs and its voltages are ok, but the MB standby LED still does not light up, then the MB is bad.
(5)If the PS fan and all fans connected directly to the PS run, the PS voltages are ok, and the MB standby LED lights up, but the fans connected to the MB and all other lights do not work when the 'Power On' button is pushed, then make sure the computer case power button's wires are securely connected to the correct MB terminal(POW-ON, Power On, etc.), and that the wires are not shorting out(bare spots). If that's ok, then remove the power button's wires from the terminal, and
momentarily short out the MB terminals with a screwdriver. If the fans connected to the MB and all other lights work, then replace the start button assembly.
(6)If the fans connected to the MB and all other lights do not work after troubleshooting the 'Power On' button, then the MB is bad.
(7)If all fans and lights work, but there's no display, then either the MB, CPU, video card, or memory is bad.
Remove the video card and the memory, and reinsert them a few times. Make sure the video card is firmly seated with a good push, and that it does not raise out of its slot when its hold down screw is installed. Try the memory one module at a time, and in different slots. If no luck, then these components have to be swapped out to find the bad one.
(B)MB Has No LED's:
(1)If the fans and lights do not come on when the 'Power On' button is pushed, then slightly raise the PS main power connector out of the MB connector, and push the start button again. If the fans and lights come on, then either the PS or MB connector is bad.
(2)If the fans do not run and no lights come on when pushing the 'Power On' button with the PS main power connector slightly raised, then test the PS as described in (A2) and (A3).
(3)If the PS is ok, then continue troubleshooting as described in (A5)-(A7) above(excl. the MB standby LED).
If that's ok, then clear CMOS by either removing the CMOS battery, or with a MB jumper(see your MB's documentation for the proper jumper).
If no luck, then connect only the power supply, MB, CPU, video card, memory, case speaker and power button, and monitor, make sure the power supply's voltage selector switch is set to the correct voltage, the PS connection to the MB as well as all cards and the memory are all firmly seated(sometimes a hard push is required to seat them properly), and place the MB on a piece of cardboard.
If the system starts up and there's a display with the MB on cardboard, but things fail to work when the MB is connected to the case, then check for a grounding problem with the MB(usually a metal standoff contacting a MB printed circuit or component).
(A)MB Has LED's:
(1)If the MB standby LED does not light up when you turn on the power supply's switch, then slightly raise the PS main power connector out of the MB connector a little. If the MB LED lights up, then either the PS or the MB connector is bad.
(2)If the MB standby LED does not light up by doing the above, then test the PS by keeping it connected to the MB and jumpering the green wire with any black wire on the back of the PS connector. If the PS's fan does not run, then either the PS, AC power cable, AC power cable connector, surge arrestor, or wall outlet is bad.
(3)If the PS fan runs, then check the following with a voltmeter with the fan running:
yellow wire and a black wire- +12V
red " " " " - +5V
orange " " " " - +3.3V
If these voltages are not up to spec, then the PS is bad.
(4)If the PS fan runs and its voltages are ok, but the MB standby LED still does not light up, then the MB is bad.
(5)If the PS fan and all fans connected directly to the PS run, the PS voltages are ok, and the MB standby LED lights up, but the fans connected to the MB and all other lights do not work when the 'Power On' button is pushed, then make sure the computer case power button's wires are securely connected to the correct MB terminal(POW-ON, Power On, etc.), and that the wires are not shorting out(bare spots). If that's ok, then remove the power button's wires from the terminal, and
momentarily short out the MB terminals with a screwdriver. If the fans connected to the MB and all other lights work, then replace the start button assembly.
(6)If the fans connected to the MB and all other lights do not work after troubleshooting the 'Power On' button, then the MB is bad.
(7)If all fans and lights work, but there's no display, then either the MB, CPU, video card, or memory is bad.
Remove the video card and the memory, and reinsert them a few times. Make sure the video card is firmly seated with a good push, and that it does not raise out of its slot when its hold down screw is installed. Try the memory one module at a time, and in different slots. If no luck, then these components have to be swapped out to find the bad one.
(B)MB Has No LED's:
(1)If the fans and lights do not come on when the 'Power On' button is pushed, then slightly raise the PS main power connector out of the MB connector, and push the start button again. If the fans and lights come on, then either the PS or MB connector is bad.
(2)If the fans do not run and no lights come on when pushing the 'Power On' button with the PS main power connector slightly raised, then test the PS as described in (A2) and (A3).
(3)If the PS is ok, then continue troubleshooting as described in (A5)-(A7) above(excl. the MB standby LED).
It's possible you have the dip switches incorrect. Here is the site that may help you if you don't have the manual.
You have to scroll a little on that page.
I hope this helps.
Cindy
You have to scroll a little on that page.
I hope this helps.
Cindy
- Thread starter
- #5
The PS (Antec 450W) fan is working correctly and the voltages are correctly set. The CPU Fans, all external fans and even the Power LED for the MB turn on correctly when the Power On button is pressed.
Standoffs have been checked, MB does receive power correctly, the indicator light on the MB is on. However, no BIOS or diagnostic beep (or Power-On Self Test) occurs as was indicated by the manual.
The memory (2 Kingston 256 MB ECC RDRAM + 2 Kingston 128 MB Non-ECC RDRAM) were placed in properly and should function correctly. I am in the process of testing the RAM and gfx card to see if either of these is faulty (using friend's MB, same model). If these check out, the only remaining problem would be the CPU or MB itself.
One possible problem: The CPU is bad, or that it is not properly secured, if this is the case, reattaching it should do the trick (I will do this at a later time, and also take the CPU itself to be tested on my friend's MB). If all components, CPU, RAM, GFX card, PS are working, then the MB must be faulty.
Standoffs have been checked, MB does receive power correctly, the indicator light on the MB is on. However, no BIOS or diagnostic beep (or Power-On Self Test) occurs as was indicated by the manual.
The memory (2 Kingston 256 MB ECC RDRAM + 2 Kingston 128 MB Non-ECC RDRAM) were placed in properly and should function correctly. I am in the process of testing the RAM and gfx card to see if either of these is faulty (using friend's MB, same model). If these check out, the only remaining problem would be the CPU or MB itself.
One possible problem: The CPU is bad, or that it is not properly secured, if this is the case, reattaching it should do the trick (I will do this at a later time, and also take the CPU itself to be tested on my friend's MB). If all components, CPU, RAM, GFX card, PS are working, then the MB must be faulty.
I think you are doing a great job! Make sure when you work on this computer that it's stripped to the power supply, motherboard,cpu and memory. Reseat the cpu and clear the cmos, if that doesn't work then check the cpu at a friends house. It sounds like you are on your way to getting it fixed soon.
Happy hunting.
Cindy
Happy hunting.
Cindy
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