Question Faulty ram or something else

Feb 20, 2019
My computer
Ryzen 5 1600
B350m gaming pro
Gtx 1060 6gb
Corsair vengeance lpx 1x8gb 2400

This was the computer that I had built almost a year back but was unsatisfied with it because it never had enough ram to do multiple tasks at once. I had bought another stick of Corsair vengeance lpx (1x8gb 2400) but when I had installed it into the other ram slot the computer would turn on (leds on motherboard) and fans would start spinning but no picture was displayed (I’ve made sure my monitor works with second pc). I then switched the original stick to see if the slot was the problem and left the new stick out and it booted. Then tried just the new stick and no boot on either slot. I kept switching the rams sticks between slots and reseated my gpu and cpu multiple times (no bent pins on cpu) and got it to work once. It booted like normal with both sticks and was running ok. The computer recognized both sticks but said one was 2133 and the other was 2400 in the bios. In task manager it recognized 16gb of ram but was only using 8gb. I decided to try to switch the ram sticks between slots (to try to get it to use 16gb) which got me back to square one with no boot with two sticks and only the original one working. I’ve updated my bios and that hadn’t changed anything. Any help is appreciated.
they are not showing anywhere on board qvl list try the new stick in slot one and if it boot if not leave ram in and dios a cmos then try to memtest it i would also use cpu-z spd and memory tab to compare both specs of these ram new one might use higher settings ,
Memory modules sold as Singles have no guarantee to be compatible in any configuration other than as a Single module. Other configurations you decide to make have no guarantee to be compatible together.

Workarounds to get extra memory to work include:
Lower clock speed
Relax DRAM timings
Increase DRAM voltage