Question PC Only Boot When RAM in Channel B Slots

[SamuraiMelon]

Hi,

I have a Gigabyte Z370 Motherboard with 2x 8GB XPG GAMMIX D35 RAM and i5-8600 CPU. I've tried to run in 2 channel configuration but the PC will not boot no matter what slot configuration, with 2 sticks.

My main concern is that it won't POST even with a single stick in slots DDR_4, DDR4_2, which is specified by the manual as Channel A, but will in DDR4_3 or DDR4_1 (Channel B).

Would this issue more likely be the CPU as its both slots on the same channel that won't boot (single or dual), or a motherboard issue?

Thanks

 

[zinkles]

A very weird solution is suggested here, might as well try it and see.
https://www.reddit.com/r/buildapc/comments/cr6ot5/solved_dual_channel_ram_not_working/

 

[SamuraiMelon]

Thank you but unfortunately the heatsink is an intel one with the push in pins, so can't screw it too tight.

 

[zinkles]

Could be a CPU issue. While it also could be a motherboard issue, I think because the memory controller is in the CPU ( most new machines), its likely its the culprit.

If you can test the CPU in another machine, and if all RAM slots work in the other machine, then the CPU is fine, and the motherboard is the issue.

 

[SamuraiMelon]

Unfortunately I don't have another MB to test it in. The CPU is 2nd hand, I'm gonna try cleaning it and reseating it. Perhaps there's a residue of thermal paste from where it came from. Hopefully that'll sort it.

 

[zinkles]

I doubt cleaning the thermal paste will help, but reseating it might help.
If all else fails, you'll have to get the CPU checked via a computer shop nearby, where they can test it for you. (be sure to describe the issue to them and what needs to be tested.)

 

[geofelt]

Is this a new problem?
If so what might have changed since all was well?

One common cause for strange ram issues like yours is a bent pin in the motherboard cpu socket.
It is all to easy to cause such damage if you needed to smoosh the cpu around to seat it in the socket.

A damaged pin can often be nudged back in place with a needle.

You may want to read my stock instructions on mounting the intel stock cooler:
----------------how to mount the stock Intel cooler--------------

The stock Intel cooler can be tricky to install.
A poor installation will result in higher cpu temperatures.
If properly mounted, you should expect temperatures at idle to be 10-15c. over ambient.

To mount the Intel stock cooler properly, place the motherboard on top of the foam or cardboard backing that was packed with the motherboard.
The stock cooler will come with paste pre applied, it looks like three grey strips.
The 4 push pins should come in the proper position for installation, that is with the pins rotated in the opposite direction of the arrow,(clockwise)
and pulled up as far as they can go.
Take the time to play with the pushpin mechanism until you know how they work.
Orient the 4 pins so that they are exactly over the motherboard holes.
If one is out of place, you will damage the pins which are delicate.
Push down on a DIAGONAL pair of pins at the same time. Then the other pair.
When you push down on the top black pins, it expands the white plastic pins to fix the cooler in place.
If you do them one at a time, you will not get the cooler on straight.
Lastly, look at the back of the motherboard to verify that all 4 pins are equally through the motherboard, and that the cooler is on firmly.
This last step must be done, which is why the motherboard should be out of the case to do the job. Or you need a case with a opening that lets you see the pins.
It is possible to mount the cooler with the motherboard mounted in the case, but you can then never be certain that the push pins are inserted properly
unless you can verify that the pins are through the motherboard and locked.

If you should need to remove the cooler, first run the cpu to heat it up and soften the paste before shutting down and powering off the pc. That makes it easy to unstick the old cooler.
Turn the pins counter clockwise to unlock them.
You will need to clean off the old paste and reapply new if you ever take the cooler off.
Clean off old paste with alcohol and a lint free paper like a coffee filter.
Apply new paste sparingly. A small rice sized drop in the center will spread our under heat and pressure.

It is hard to use too little.
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