PC not POSTing [fans running]

[Kyshu]

Hello everybody!

I'm having a little problem with my PC:
It won't boot up properly anymore after working fine for about a year.
When I turn on the computer, the case fans as well as the CPU fan turn on, as well as the LED fan on the front. The monitor shows no signal though.

My system:

MB:
Gigabyte GA-970A-D3

CPU:
AMD FX-8120 @ Standard clock (not OC'd)
Cooler:
Enermax ETS-T40-TB (crappy one )

GPU:
(now) Gigabyte GeForce GTx 670 OC (WindForce 3X)

PSU:
be quiet! Pure Power L7-730W

RAM:
Corsair XMS3 RAM, 2x4GB DDR3-1333MHz


When I used the computer (the system is mainly for Gaming, browsing, video editing, etc.; at the moment I was browsing, so the system wasn't under Load), it suddenly shut down without a warning, like as if there was a power outage in the house (which there wasn't, I asked everyone else, and the lights didnt go out either). No BSOD, no error message, just a straight crash to a black screen, with the PC being powered off.

When I turn on the system again, I notice that the system shortly "runs warm", so to speak, and the fans start running, "preparing" for boot, but then slow down again, and the monitor receives no signal. I deattached everything except the MB and the CPU+Cooler, but the system still doesn't POST, judging from the CPU fan slowing down.

Thinking it might be a problem with my graphics card, I RMA'd my old Gainward GeForce 560 Phantom, and bought a new Gigabyte 670 OC, which didn't fix the problem though.

Following the sticky in the forum, I tried breadboarding the system, which didn't help either, I still get no Signal from the Monitor.
I connected the case speaker to the SPEAK connector on the motherboard, hoping it would give me a beep code hinting at the cause of the problem, which it didn't. Strange enough, when I connect my DVD-drive to the breadboarded system, it gives out 2 short beeps (not coming from the little connected speaker, but the MB itself?)


Things I've tried so far:

- Reseating every component

- Making sure all the cables are plugged in (24-pin main power cable for the MB, 8-pin cabe for the CPU as well as PCI-e-cables when GPU is connected)

- Breadboarded the system, starting it up by connecting the 2 PWR-SW pins on the case IO-panel thingy on the MB (what it is called, actually? )

- cleaning the whole MB from dust, and checking if anything is inside the PCI-slot (as the problem isn't just with the GPU plugged in, but even with the breadboarded system without GPU, I don't think the PCI-slot is the problem)

- Doing the green-cable-black-cable-paperclip-Check on the PSU. The fan turns fine.

- Got myself a multi-meter and checked the connections on the PSU.
I'm no electrician at all, but they don't seem to have the right values, and most of the connections have too much voltage, if I read it right.

- Did multiple CMOS CLR's and took out the CMOS battery several times (could that be empty? I put in an old one from my very old PC, that didn't help it though, when the shops are open again, I will get a new battery.


I am suspecting that my problem is the PSU. I am afraid to break anything though and seeing how I failed just checking the voltages, I would rather leave checking the PSU to a hardware shop.
Also, as the PC just shut down without a warning and none of the other rooms having a power outage or lights going out, I think that it would be the PSU, and that it just fried?
I didn't check particularly, but I didn't see a green LED light up on my MB when powering it on. Then again, I never saw that thing before, either.


Do you guys have any further ideas on what I could try? I really don't know what else to do know, and it's somewhat frustrating having to write a research paper on Computer Science on a PC/laptop that you share with someone else .. oh well, no other choice for the time being, haha

Tell me if you need any other info!
Greetings from Germany, Kyshu



Don't...

Bump posts


http://www.tomshardware.com/forum/283384-33-read-first

 

[adycopilu]

Hello,

Most of the times, no beep sound during POST means PSU issue. However, that shouldn't start the fans, or so I suppose. Therefore I also suspect some damaged CMOS. Good thing you have Gigabyte which provides Dual-BIOS so maybe you can try to restore it (check your manual about the procedure), but only after you rule everything else out and have literally no other option (and you are sure all the other components are ok, especially the PSU).

The fact that the fans spin up to full rpm and then slow down it's normal, provided that your motherboard controls them by PWM or voltage. They start up at full speed with no speed control, but after the speed control chips from the motherboard boot up, they will slow the fans down, according to the settings in BIOS. You can refer from that the motherboard is starting somehow and it's also receiving some power. Whether enough power is provided or if the start up is complete, I don't know.

You can ignore the CMOS battery for now, that one is used only to keep the BIOS custom settings during power outages. Without the battery, BIOS should load the default configuration settings.

The paperclip trick for starting the PSU is not that relevant. It only shows that the PSU can start with no load. I have a PSU that starts with a paperclip, but can't start the system (as it used to).

One suggestion, but it's long shot, and you probably already tried: maybe the PCIx slot is broken, try to use the other one with your video card. Also borrow some PSU from a friend, it might be the main cause. Unfortunately, no other idea, you pretty much did anything possible.

 

[Kyshu]

First off, thanks for the answer! Had to write my reearch paper yesterday, so had no time to answer, haha.

I went to the local tech shop yesterday, and got my power supply checked. He said it was fine, so I suspect the error in either the Motherboard or the CPU, I would guess the motherboard since the LED doesn't light up at all, not even with another PSU. I am probably gonna get the motherboard switched out Monday from the retailer where I bought it, and see how it goes then.
I have been taking my CPU out in the procedure of re-seating it, and inserted it back into the socket, which failed and I saw that some of the pins were bent. I'm gonna check them right now, if I can fix that and rule out another cause, although it most likely is the motherboard

Greetings!

 

[Kyshu]

Alright, so I checked and fixed all the pins on my CPU and reseated it, attached the cooler etc. -> still no signal.
I played around with the RAM modules, switching them around, trying different slots, etc.
Anything else I could try?

Edit: Oh, and I tried the other PCI-E-slot, too! Made sure there's no dirt in either of then as well, as well as in the ram slots

 

[adycopilu]

You've pretty much ruled out most of the possibilities. As you said, it might be the motherboard, although I'm not sure about which LED are you talking about? Is it the system LED or some LED on the motherboard? What should it indicate?

I would not rule out CPU however. Bent pins can be very difficult to fixed and even if they seem alright from a visual perspective, it is still possible that they don't do perfect contact. But since this issue occurred during your troubleshooting try-outs, try to switch the motherboard, as you said. Tell us how all goes!

 

[TenPc]

"checked and fixed all the pins on my CPU " Fixed the pins? Please elaborate. You can straighten leaning pins but not if they are bent.