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Lights on, fans on, no beeps, no POST.

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May 25, 2012 1:40:19 AM

Hi, I've just built a new computer for a friend of mine, and right on the first boot the lights went on, the fans worked, but there was no POST nor any kind of video. I then took the following measures:
1. Went through all the steps in this thread http://www.tomshardware.com/forum/261145-31-perform-ste... except breadboarding, I've never done it and I don't really know what a suitable surface would be.
2. Another fellow PC-builder suggested to me it could be the memory, so I switched the brand new memory at the store for another of the same type, installed, and the problem persisted. I also tried the other slots, to no avail.
3. The case had no speaker, nor did the MB, so I bought one of those small Piezo speakers, and installed it, but didn't hear any beeps at all.
4. I tested her display and all power and video cables, they all worked.
5. Tried to turn it on without the memory, no beep. Without the HD, no beep. The MB doesn't have Onboard video, so I didn't try turning it on without the GPU.

So, to sum it up: Everything is brand new except the HD and (as far as I can tell) correctly installed. The PSU, GPU and CPU fans work. The DVD drive and HD both make "turning on noises". The light on the MB is green, however, it doesn't beep, POST, or display anything on the screen.

The specifications are as following:
CPU AMD Bulldozer FX 4100
MB ASUS M5A78L
RAM Kingston HyperX DDR3 1333mhz 1.5V
New, Stock Cooler
Video ATI Radeon HD 6670
PSU C3 Tech 450W GPB450S 24P
HD Samsung 80GB

Well, that's it, any help would be hugely appreciated, my friend works from his computer, so he needs it ASAP.

More about : lights fans beeps post

May 26, 2012 3:02:07 PM

Shameless bump guys, I really need some help =/
May 27, 2012 10:42:19 AM

for a new builder this will sound ridicilous but trust me and try it ,
remove all cables from the pc power plug usb ports display speakers etc.....
press the power button for 1 min exactly and replug everything and power up
this should break up any extra electric charges shorting the mb
Related resources
a c 122 B Homebuilt system
May 27, 2012 2:58:51 PM

First:
http://www.tomshardware.co.uk/forum/274745-13-step-step...
to make sure you did not overlook something simple.

Second:
I am unfamiliar with modern AMD systems so I do not know if your motherboard requires a BIOS update before you can use a BD CPU with it.

Third:
From your parts list, the first thing I would suspect is your PSU.

Pull the system apart and breadboard it. The first thing that does is remove the case from the suspect components.

Breadboard with just the PSU, motherboard, CPU & HSF, and the system speaker. When you turn on the system you should hear a string of long beeps telling you that you have memory problems. Silence indicates a problem with the PSU, motherboard, or CPU (rarely). And you have an off brand PSU.

The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.
http://www.tomshardware.com/forum/261145-31-read-postin...

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...
Check the original thread for ideas about what to use for a surface.

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. At this point, if you do not have a system (internal case) speaker, you really need one.

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, LED's, or fan activity:

Check for line power at the PSU input. Extension cords, power strips, and power cords do fail.

If you have power and no beeps, suspect components in likely order are PSU, motherboard, and CPU.

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%. The green wire should read 5 volts and drop to around 0 volts while you press the case power switch.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. The 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.
May 27, 2012 8:19:19 PM

Thanks for the help, but nothing really worked. I did everything you recommended, including breadboarding, and it powers on, but no beeps at all, even with just the PSU, MB, CPU & HSF.

I will try to get a refund and a new PSU by Tuesday, hope this works =/
June 3, 2012 7:42:27 PM

Well, initially it was the BIOS, which had to be updated with another, older processor on, which I didn't have. Later, the PC stopped working again, and after much experimentantion it works perfectly without the DVD drive connected to the IDE slot, for some reason.
!