B350 HDV won't spin up [SOLVED]

Hello there,

I am very new to computer assembly and recently acquired parts for my first one.

I got the following equipment:
- ASRock B350 HDV motherboard
- AMD Ryzen 1600 CPU (with its own cooler from the box)
- DDR4 2133 MHz 8GB J&A RAM (2 pieces)
- ZOTAC GTX1060 6GB GPU
- WD Blue 1TB hard drive
- EVGA 500W power supply
- AeroCool LS-5200 chassis

Case is: whenever I turn on the power supply, the LED on the power button blinks blue and stays like that forever. No boot, no fan spin up, only the flashing LED I get.

I have installed the motherboard, plugged in all above components, plus wired the cables hanging out from the chassis front panel.
Wiring should be correct: fans connected to the CHS_FAN slots, USB's to USB slots, HDD connects through SATA, GPU gets the 6 pin cable, CPU gets the 4 pin cable, large ATX20+4 plugged in.

I have sent back the motherboard to the vendor, they concluded it has no problems. The PSU spins up when its green and earth wires are shorted.

What could be the problem? Any help is appreciated. :)

Thanks for the suggestion! The CPU 12V cable is in its place though and fits perfectly.

The RAM might be a different case. In the manual, it states that it supports 2400 MHz sticks. Is it an upper or lower limit for frequency? I read that 2133 MHz rams work just fine with this motherboard.

I noticed that the blinking appears with minimum setup (alas: CPU, memory sticks and PSU plugged in) as well.

Cheers!

I only found non-English links to the model, as mostly Hungarian stores sell this product.
J&A is a manufacturer in Taipei.

Specs:
- Frequency: 2133 MHz
- Casing: DIMM
- 288 pins
- Size: 8GB
- Error correction: Non-ECC
- Power: 1.2V

Update: it wasn't the memory or the PSU, but the CPU had some pins bent for unknown reasons. I had to buy a replacement and with it, the computer spins up.

Thank you for the help! This thread can be closed.