Question Overvolted ram, now idk what causes blank screen

Mar 27, 2020
So i was looking at my ram and i saw that i had 4 ram cards but only 6 gb of ram were showing on windows (see specs -->) and i thought to myself there must be an issue why my other 2gb of ram are not showing. Looking on the ram card i saw that kingston were at 2.0v and the corsair at 1.8v and i thought that the missing ram must be because of low voltage (not a computer whizz) and i started looking online for solutions

Kind of a newbie that got overexcited at the idea and now idk what to do. Not really sure if its the ram slot or the memory thing on the cpu or whatever else kind of problem moght be but can anyone help me diagnose this?
As soon after i saved settings in bios it passed post and at the windows logo it went dark but pc was still on.

Have tried:

-resetting CMOS by pulling battery out 5 min and jumpstarting the mobo

-testing memories currently but seems like no memory is faulty

-reseating the cpu on the mobo

-airblowing the ram slots

-switching gpu slot

When either channel 2 or 4 has a ram card in it, the pc starts, theres no image but cpu fan is spinning although the gpu fan spins then stops then spins again. No error beeps, no image .
When channel 1 or 3 has ram it works as normal.

Is it a faulty ram slot or a cpu memory controller problem? How can i tell?


My mobo: gigabyte MA790x-ud4
My cpu: amd phenom II x4 940 black edition 3.0 ghz am2+
My ram: 2x kingston hyperx KHX6400D2LLK2/2G ( this is where the confusion started)
And 2x corsair cmx2x2048-6400c5c