1st Time PC Builder with a Question

October 30, 2016 2:37 PM

I'm trying to build my own gaming PC and have hit a snag. The motherboard powers-up but a few seconds later powers back down, then repeats.

I've never tried to build a PC before and am using online resources to both spec out the parts and walk me thru the build. I've connected the pieces in a test build and everything appears to be getting power, but the board just cycles up and down. Each power cycle takes about 8 seconds. What's the most likely issue? What troubleshooting steps should I try?

Here are the system specs: Gigabyte GA-Z170X-Gaming GT motherboard fitted with a Intel Core i5 6600K 3.90 GHz Quad Core Skylake Desktop Processor and cooled by a Corsair Hydro Series H100i v2 Extreme Performance Liquid CPU Cooler. The video card is a Gigabyte GV-R939G1 GAMING-8GD G1 Gaming Graphics Card AMD R9 390 512 Bit GDDR5 8GB 2xDVI/HDMI/3xDP. The power supply is a Corsair RMx Series, RM650x, 650W.

posted by Jamesonian to Computers & Internet (13 answers total)

Best answer: That happened to me when I placed the ram in every other slot. Try putting them next to each other or vice versa.
posted by littlesq at 2:53 PM on October 30, 2016

That sounds like something that happened to me with a faulty PSU.

Are there any error messages on the screen?
posted by lmfsilva at 2:54 PM on October 30, 2016

remove the gpu and use the onboard graphics. is anything displayed? any beeps?
posted by andrewcooke at 2:55 PM on October 30, 2016

(removing suggestions posted above so as not to duplicate)

First of all, make sure that all power connectors are securely attached on the motherboard. There should be one 8-pin connector for the CPU on the motherboard (just above the CPU) as well as the standard 24-pin connector. On the video card you have specified, there should be one eight-pin connector and one six-pin connector going from the PSU to the back of the video card.

Barring obvious connection issues, these kind of things tend to be either the motherboard or the power supply. Is the machine posting (do you see a BIOS) or do the fans just spin up and down? You may need to remove the CPU and check the pins below to see if any of them are bent. Are all the fans spinning up when the machine starts, or just some of them?

I had this happen quite similarly and ultimately it was a bad motherboard (also a Gigabyte, weirdly).
posted by selfnoise at 2:56 PM on October 30, 2016 [1 favorite]

Make sure all the power connectors are plugged in the the motherboard.

Re-seat all the boards, especially the RAM.

Try swapping the RAM modules in a different order of applicable.

Try using only one stick of ram at a time.

Start up with a minimum of components and add one at a time. Use another video card if possible.

Test the power supply on another computer.

Fans are usually the cheapest components and may not be well QC'd. Make sure all the ones you use are working.
posted by Yorrick at 2:57 PM on October 30, 2016

This also sounds like a simple short, with one loose screw or wrongly placed motherboard stand or whatever. Due to assembling a system in its case and seeing these same symptoms many times, my first step now in building a new system is to assemble the bare minimum of parts to get the system to post with the motherboard sitting on its box on the static pouch and not in the case. This way I see if the bare minimum of parts work before I get too far in.
posted by BurnMage at 3:03 PM on October 30, 2016 [2 favorites]

I've seen this when the motherboard power is connected but the CPU power is not.
posted by Xany at 3:21 PM on October 30, 2016 [3 favorites]

It might just be a bad motherboard, if you try all the things recommended above and it still won't work. One last thing to look at, if all else checks out and because it is a pain to do, is to take off the cooler and CPU and check that the CPU socket pins are all straight.

I'm planning a build and was looking at that motherboard, as well as others. The reviews on Newegg suggest that it can be a somewhat buggy board and not very user friendly. Looking at reviews across Gigabyte's line over the past few days, it looks to me like they've had some problems with quality control on many of the Z170 boards. The PSU is much less likely to be bad.

Because this is an expensive board, there are not very many completed builds using it on Pcpartpicker. However, I will note that all of them used higher wattage PSUs, though I highly doubt that is the problem.

You don't mention what RAM you are using, but I assume that you checked the Memory compatibility list and chose accordingly. RAM sticks can be surprisingly hard to seat properly.

It can be a frustrating and time-consuming process, I know, but you can do this.
posted by monopas at 6:24 PM on October 30, 2016

I've also seen this kind of behaviour when the storage that holds the boot information has been corrupted. There should be a jumper you can close somewhere on the board to reset the NVRAM - try doing that (with the power off) and then powering the beast up again.
posted by pharm at 2:28 AM on October 31, 2016

There are good suggestions above. For me, the clue was that the system didn't even post (no LED readout on the motherboard). The problem turned out to be a loose connection at the PSU — the motherboard cable was getting dislodged every time my hand was in the neighborhood.
posted by ck49 at 3:08 AM on October 31, 2016

Re-seat all the boards, especially the RAM.

This, this, this.

I built a very similar system a few months back (including a Gigabyte motherboard of a similar model, not quite 100% the same). It had the exact same behavior, and I was convinced either it was the power supply or the board itself that were faulty. As a last ditch effort, I removed everything and started adding things back in one at a time. It turned out to be the RAM configuration.

Try just a single stick of RAM at a time, and check your manual -- there's specific slots you're supposed to use if you're only using 1 stick, or 2 sticks. That's what tripped me up, and once I had my (two) sticks in the correct slots everything was fine. (I can't load the manual online right now, but from memory it was a weird configuration, not the slots I assumed originally).
posted by tocts at 8:14 AM on October 31, 2016 [2 favorites]

As andrewcooke asked, are there any beeps? The manual should give clues about what issues the beeps indicate, and the absence of beeps might mean you can cross those issues of the list.
You don't mention how far the boot process gets. Is anything appearing on screen? ie. any BIOS/POST info?
edit to add: I'd also probably try the PSU in another known-working box just to be sure. Bad RAM is just bad RAM needing replacement. A bad PSU can take everything else out with it.
posted by quinndexter at 10:28 PM on October 31, 2016

Response by poster: The RAM positioning seemed to be the problem, so I repositioned them as advised and the system is running.

Thanks!
posted by Jamesonian at 10:17 AM on November 5, 2016 [1 favorite]