Djoubert

Thanks for the reply. The problem manifested itself as I test-benched the basic parts before even putting them in the case. The only parts I ever plugged in were those listed above - kept it as skinny as possible in the circumstances. As for the "RAM in every slot" (wish saying it aloud wasn't funny...), l arleady tried it, and it did got rid of the "RAM" debud LED, but not the "CPU"'s... Thank you for the suggestions. I already had tried most of them, except borrowing different DDR4 RAM sticks; maybe I should get more tech-savvy friends I read that Ryzen chips can be finicky with RAM, and the exact GeIL model I have isn't officially listed among the compatible RAM with MSI B-350 mobo, but 1) still weird that "CPU" debug LED lights up, and not "RAM", and 2) most similar cases I've heard of didn't prevent BIOS from booting. Anywho, I got an RMA for the CPU, as it seems the most logical culprit at this point ... I will keep you posted when the new CPU arrives. Thanks again for the advices, much appreciated!

First build, using the following: - CPU: Ryzen 5 1600 - Mobo: MSI B-350 Tomahawk - RAM: GeIL Evo Potenza DDR-4 3000MHz (PC4-24000), 2x8GB - PSI: SeaSonic M12II 520 Bronze - VGA: GIGABYTE GTX 1050 Ti At the first boot, "RAM" and "CPU" EZ debug LEDs of the mobo turn on. Nothing on the monitor, even after 10 minutes (AMD's initial boot time being notoriously long), thus cannot even gety to BIOS and update it. I notice that a resistor on the backside of the mobo, right under the CPU socket, is loose and broken. Thinking that the mobo is the sole problem here, I get it replaced. Upon receiving the new mobo, the exact same symptoms appear. CPU plugged in, cooler plugged in, mobo plugged in, monitor plugged on VGA, CPU placed correctly on socket, but "RAM" and "CPU" debug LEDs turn on. Reseting the CMOS didn't change anything; static definitely wasn't an issue here. Weird thing is, if I place RAM in slots NOT recommended for a 2-stick setup (ex.: DIMMA1 & DIMMB1 instead of DIMMA2 & DIMMB2), "RAM" debug LED turns off, but "CPU" LED stays on. So... is this just a case of busted CPU (maybe due to the broken resistor on the first mobo)? What am I missing here?