Question Gigabyte Z390 UD - 12V 2x2 power connector

[Anton Vind]

Hello everyone,

I'm currently building a new pc. Motherboard is Gigabyte Z390 UD, GPU is RTX 2080 SUPER, CPU i9-9900k and RAM is 32 GB DDR4 3600 MHz.

For power connections on the motherboard, there's both a 2x4 12 V connector, and a 2x2 12 V connector. The PSU I have (850W from Corsair, btw.) does not have the cable for the 2x2 12 V connector, so it's only connected to the 2x4 12 V connector at this point. Don't I need a 2x2 12V cable as well, given the other components I have installed?

The system won't really boot - the PSU fan does not even spin, it only moves very momentarily and stops, and then after some seconds the RGB RAM begins to illuminate. At this point I suspect that that happens because only the 4x2 12 V connector is connected, not the 2x2 12 V connector as well. Do I need a cable for the 2x2 12 V connector? If yes, where can I buy such a cable?

Greetings,
Anton Vind

 

[popatim]

That is for extra Overclocking power.
The symptom you describe can be cause by the PSU detecting a short and not turning on fully to save itself and your system. Remove the motherboard and look for something that might cause a short, such as a misplaced standoff. If you don't find anything then breadboard the system outside of the case and see if it still happens.

As always, do not use modular cables from another PSU unless you are 200% positive they are compatible.

 

[Anton Vind]

That is for extra Overclocking power.
The symptom you describe can be cause by the PSU detecting a short and not turning on fully to save itself and your system. Remove the motherboard and look for something that might cause a short, such as a misplaced standoff. If you don't find anything then breadboard the system outside of the case and see if it still happens.

As always, do not use modular cables from another PSU unless you are 200% positive they are compatible.

So even if my intent is to overclock the CPU to 5.00 GHz, I won't have to use the 2x2 12V connector? Also if you think about the other components that I have?

Regarding the PSU, what is meant with "short"? Also with "standoff"? I'm not exactly familiar with those terms.. Maybe it's worth mentioning that the case I have is a bit old and I've lost quite some of the six "screws" that are supposed to keep the motherboard in place in the case. In fact I think only three screws were available to mount the motherboard. That is also why I have ordered a new case, because that what planned to be done anyway.

Is there a way to test the system without having a case? You mentioned it a little bit - are you able to elaborate a bit on that?

I decided to order a 2x2 12V cable - but I guess I won't have to use that anway then...
https://www.av-cables.dk/intern-pc-...7KC-o8GQt9CwrPB8Rzz3FTim41sDqtRYaAnl5EALw_wcB

Thank you for your answer - I am eager to get this build up and running!