Question Installed new ram but no signal on monitors

Apr 17, 2019
So i have a motherboard
asus m5a78l-m/usb3
supports up to 32gb ram 4 slots
I have just bought 4x8gb ram all same manufacturer and speed
ram specs 8gb pc3-12800u ddr3 1600mhz

when i put two in the motherboard recognises this and all is fine but when i trg a third or fourth no joy, I have tried all sticks singally and duo they all work just only as two and not 4
I have evn put 2x8gb in and 2x4gb and thats accepted so mobo can clearly take more than 16gb just not sure what i am doing wrong

Is it maybe a bios setting or something

any advice much appreciated

Check the CPU socket pins to make sure they are absolutely perfect. Any slight change can cause a problem. If you are using an aftermarket CPU cooler, make sure it is not too tight or loose. Once everything is double checked, should you still have a problem, you may need to try another motherboard or CPU.

Which slots do you have them installed in? Did you test to see if all slots are working properly?
Apr 17, 2019
So all 4x8gb ram work, but not together, I have placed them in all the slots at different times and work fine, I have even mixed them up on duo ie ram 1 with 2,1+3,1+4,2+3,2+4,3+4.
I can only get two to work together at any one time.
I had 2x4gb in previously so I even tried 2x8 and 2x4 together and that worked when I tried 3x8 as 2x8+2x4 is same as 3x8 but nope that never worked.
I am on latest bios
I have tried a CMOS and still the same issue
whenever I put 3 or 4 sticks of 8gb I get power on fans turning keyboard lighting up but no signal for monitors

Not sure if it matters but I don't have a graphics card in so not sure if its the onboard graphics that fail with too much ram, not even sure if that's a thing

mobo is asus m5a78l-m/usb3
cpu amd fx 4170 4.2
ram is 8gb ram pc3-12800u 1600mhz non ecc 1.5v cl11 ddr3

do I need to set something in bios?
Apr 18, 2019
Did you get these RAMS from ebay by any chance?
I have exactly the same motherboard , I bought some shady RAM sticks from ebay, i bought 4 sticks but only can connect 2 like your case. Maybe those AMD RAM only stuff they sell sucks so hard you can only install 2 sticks instead 4, now I'm trying to sell 2 sticks for someone who only wants 8gb for his machine.
Last edited: