New PC unable to POST + Actions I Have Taken to Attempt to Solve

[docjack]

CPU: i5-4460
Motherboard: Gigabyte GA-B85N Phoenix
PSU: CoolerMaster G550M

I collected all my parts today and after 6+ hours of tinkering, the PC is unable to POST. There are no beeps as the motherboard does not have an internal speaker/mini buzzer. Below are steps I have taken to attempt to identify the issue without beep codes as my guide.

Step 1. Created a breadboard with motherboard, CPU, stock CPU cooler and PSU.
> Surrounding motherboard orange LEDs light up and CPU cooler fan starts running for about 5 seconds, then everything powers down and repeat.

Step 2. Following step 1, attach two sticks of RAM (2x4GB).
> Surrounding motherboard orange LEDs light up and CPU cooler fan starts running for about 5 seconds, then everything powers down and repeat. (exactly the same thing happens)

After step 2, I believe either my PSU, motherboard or CPU is DOA. My understanding is that the motherboard should continue to run if no component is faulty, i.e. LEDs continue to light up and fans continue to run, and it would be a complete PC since the i5-4460 has an integrated GPU. Therefore, I think either my PSU, motherboard or CPU is DOA. However, I came to this conclusion without hearing any kind of beep codes as the motherboard does not come with a mini buzzer.

At this point, I will either get a mini buzzer off eBay to re-test everything, or call the seller and inform them I might have DOA parts. What should I do? I have waited 10 days for my parts to arrive and now I can't boot. Sad times. 🙁

 

[sadams04]

The B85 chipset is typically paired with a Haswell CPU. Your i5 4460 is Haswell Refresh which is newer, but that doesn't mean it isn't going to work. Some B85 chipsets need a BIOS update before using a Haswell Refresh CPU. Head on over to the Gigabyte web site and see if there is a BIOS update available for your board.

 

[cTs Corvette]

Usually when you get the power up, shut down cycle it's because of a short somewhere. I don't know if you are using new or used parts, but I would suggest inspecting all of the USB ports, checking for one that might be damaged and making contact with the surrounding metal casing. (Those metal "tabs" on the backplate are easy to accidentally stick inside the port, too, when it's in the case.)

You can also do the "paperclip test" and see if the PSU stays on on it's own. (Google it if you don't know how to do it.)

 

[docjack]

@sadams04, I have checked and verified that the CPU is compatible with the motherboard.

@cTs, they are all brand new parts. I don't really know what you're talking about but I did not see anything out of ordinary with a simple inspection at the rear I/O panel. I will try the paperclip test if I can get hold of a paperclip.

 

[cTs Corvette]

Just checking the basics here, do you have both connections from the PSU to the motherboard hooked up? The 24-pin one and the 4-pin one? Also, what are you using to turn it on?

 

[docjack]

Yes, both the 4-pin and 24-pin are securely connected to the motherboard. I shorted the Power Switch pins with a screwdriver to turn it on.

Update: I just tested the PSU with the paperclip test and the PSU fans did in fact spin. This rules out PSU as the faulty unit.

 

[cTs Corvette]

It really sounds like a short somewhere, or possibly a thermal shutdown. Are you using the stock heatsink, and if so have you verified that all 4 corners are properly clipped? The easiest way to tell is to look at the bottom of the motherboard, making sure that the center pin in all 4 corners is all the way through.

 

[docjack]

Suppose a short occurs, where would it most likely to occur? I don't think it would be a thermal shutdown though, seems very unlikely.

I am using the stock CPU heatsink. It should be properly installed, with all center pins all the way through (level with the "outer casing" under the motherboard).

 

[cTs Corvette]

With it breadboarded and outside the case, the only likely suspect is the USB ports. In the case (with nothing hooked up), the most likely suspect is a standoff in the wrong place, or the tabs on the backplate being inside one of the ports. With everything hooked up, front panel USB ports are a likely suspect, I've had them come from the factory wired backwards. (I assume that when you shorted the pins with the screwdriver, you just touched the screwdriver to the pins and removed it, right? Sorry, it's a silly question, I know, but you wouldn't believe some of the things I've seen people do.)

Bent pins in the CPU socket are a possibility, too. It's really easy to try to be super careful when installing it and do something like drop it. (Don't ask how I know that, lol.)

Without the PC speaker, it's making your life more difficult.

 

[docjack]

I'm not sure what to look for in USB ports (in the rear I/O panel) that might short the motherboard, but from what I can see, all USB ports appear to be normal.

Yes, I gently touched and immediately removed the screwdriver once the motherboard powers on.

I can't check bent pins in the CPU socket as the heatsink had been installed. I can't remove the heatsink as I don't have thermal paste to reapply after. However, I strongly believe there are no bent pins as the CPU installation was very smooth.

I know, and to make matters worse, the motherboard does not have any connections that allow a mini buzzer/internal speaker to connect, so I cannot buy one and connect it to the motherboard. 🙁

 

[cTs Corvette]

Try inserting a USB cable or thumb drive into all the USB ports (with it off, of course.) If it goes into all of them smoothly, that probably isn't your problem.

Gigabyte should be shot for failing to either include the PC speaker or a place to hook one up.

One other question, do you have the CPU fan connected to the CPU_FAN header? If not it's possible that the system is thinking it's overheating from not having the fan connected there.

 

[docjack]

Just tried all USB ports, all can be connected smoothly.

Yes, I have checked and verified that the CPU fan is connected to the CPU_FAN header.

At this point, I feel like I've done all I can do try and diagnose the problem. I'll have to give the seller a call and see what they say.

 

[cTs Corvette]

Yeah, I really can't think of anything else either, short of visually inspecting the cpu socket for bent pins.

 

[docjack]

Ok here's another interesting situation. Boy am I lucky!

So I got the motherboard exchanged. It was deemed to be DOA by the seller as they can't get it to work too (same problem - turns on then off). I got them to test the new motherboard on the spot and it worked and posted. Great!

Once I got home I tested the new motherboard with my PSU. This time, the motherboard powers on for around 11 seconds (I timed it, over an average of over 10 times) and then restarts itself, repeating the entire process. Since it worked at the seller's place, I believe the problem is the PSU. But here's the catch, the PSU passed the paperclip test.

That leaves me to deduce that the 4-pin CPU connector is faulty. I'm not sure if that is that possible, but I cannot think of any other reason for the failure to POST.

 

[cTs Corvette]

The paperclip test doesn't really test the PSU's voltage, just it's ability to come on and stay on. But it does seem strange that you would have two DOA parts.

 

[docjack]

Assuming I had 2 DOA parts from a 4-component purchase, how likely is it for that to happen? I wonder if I would have won the lottery if I bought the lottery instead on the day I bought my parts lol.

 

[cTs Corvette]

I've been building computers for a long time and I've never had two DOA's. So maybe you should have bought that lottery ticket, lol. Or you can just look at it like you're using up all your bad luck at once. 😉