Asrock X570 stuck on POST - CPU+DRAM red leds on

Question

I want to upgrade my old stationary computer, and have therefore purchased

• Ryzen 5 3600
• Asrock X570 Pro4 (which claim in the manual to support the CPU)
• and some DDR4 RAM

After assembly, and powerup the motherboard immediately lights up the CPU and DRAM leds, and the VGA and BOOT never does. The manual hints these show the problematic parts but does not go into further detail. The machine does not go any further than that in POST. No image. There is a GTX 1050 graphics card in it lifted from the previous build. Moving the RAM pair did not help. Resocketing the CPU did not help.

What does these LEDs indicate precisely, and how can I fix it?

Answer 1

It turned out that I misunderstood the manual, so the CPU did not have extra power.

Plugging in the correct cable in the motherboard allowed the machine to boot.