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Comp wont boot, no beep, just fans and lights

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April 20, 2011 1:03:44 AM

got a new power supply cuz other one broke when i was doing some heavy gaming, plugged in everything and computer turns on but wont boot (no beep and no signal to monitor). currently its breadboarded so what can i try?

already tried:
clear cmos
replugging in cables

current new power supply: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
April 20, 2011 1:55:49 AM

It should be either your Motherboard or CPU being damaged, its rarely the CPU. I've just recently had that problem (fans, led working, and no signal, beeps) and fixed by replacing my Motherboard.
You could try using another CPU just to confirm your CPU isn't dead.
Also try using another Graphics card just incase that is dead, but I don't think so.
April 20, 2011 2:18:45 AM

ugh...i think i'll add that everything turns on exept for my keyboard lights, i also tried without graphics cards to no avail...and the comp automatically turns on when i flip the power switch at the back of the power supply, turns off when i hold the power button, but if i wait too long then holding power button wont turn it off, still no beep and no monitor signal D:

i would also like an answer tonight PLZ cuz i have to finish my homework :( 
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April 20, 2011 11:24:45 AM

bojo600 said:
ugh...i think i'll add that everything turns on exept for my keyboard lights, i also tried without graphics cards to no avail...and the comp automatically turns on when i flip the power switch at the back of the power supply, turns off when i hold the power button, but if i wait too long then holding power button wont turn it off, still no beep and no monitor signal D:

i would also like an answer tonight PLZ cuz i have to finish my homework :( 


Similar problem to yours resolved by moving RAM from slots 2 and 4 into 1 and 3. Did so after consulting Tech at point of purchase. Contrary to manual instructions but worked for me.
April 20, 2011 9:00:47 PM

ill try that, thanks
a c 122 B Homebuilt system
a c 144 ) Power supply
April 20, 2011 9:06:46 PM

This will be time consuming, but ...

Work systematically through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.
The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

Breadboard - that will help isolate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboardi...

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

Make sure you plug the CPU power cable in. The system will not boot without it.

I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:
Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%. If you have a white wire (many modern PSU's do not), it should be -5 volts.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=yout...

A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.

Silence, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
April 26, 2011 11:51:28 PM

power supply is good, not dead. as for the mobo, ram trick doesnt work, its not graphics cards or anything, the cpu didnt have enough thermal grease on it but it seemed like it was running, on the mobo like i said it would turn on automatically, and i dont think the ide or whatever hard drive was spinning (because not getting power from mobo probably). checked wires probably 300 times, tried switching out, and keyboard lights dont turn on when i start computer, however my main sata hard drive spins, still no beep so lets hope the new mobo works.
February 5, 2013 4:10:54 PM

*same problem here*

Today my pc runned (other case) i bought another case + from 450W to 950W supply
i installed everything in the new case and it yust wont boot, tried everything from ram to graphicscard to cmos battery. Please help

*
No keyboard light
No bleeps
Yust a black screen
All fans are spinning
All lights (in pc are burning) (led etc.)

The same day today it worked, so it must be something?
February 5, 2013 8:31:48 PM

Make sure you plugged in that 4 wire plug that's usually near the cpu.
February 9, 2013 3:04:09 AM

bojo600 said:
got a new power supply cuz other one broke when i was doing some heavy gaming, plugged in everything and computer turns on but wont boot (no beep and no signal to monitor). currently its breadboarded so what can i try?

already tried:
clear cmos
replugging in cables

current new power supply: http://www.newegg.com/Product/Product.aspx?Item=N82E168...


Bojo, If you are getting lights, no video and no beeps the systen is not reading the first mb of memory take your memory stick or sticks out and reseed them . If you do have more then one memory stick swap them around so the stick in slot 1 is in another slot. If that soes not work reseed your cpu. It sound like when putting your power supply you may have bumped something
February 15, 2013 11:52:12 PM

dude yeah uhh, this kinda happened 2 years ago on my old pc, and if i remember correctly both my power supply and mobo got fried cuz i was stupid about overclocking. so that's it if you wanted any info on that, sorry for resurfacing a thread but it seemed someone found this on google and may have wanted to know some answers
June 12, 2013 5:18:56 PM

My computer is doing this as well and I've found a solution.

It would seem the computer thinks its on when its not. When power is reconnected it goes back to on position immediately but the boot up isn't activated.

Unplug from AC and battery if a laptop and leave for a long time. 24 hours is what I waited. Plugged back in and it was off. Pressed power and it boots normally.
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