PC does not start anymore

[Nogrod]

I was playing a game, without warning the PC just froze. My speakers made a monotonous sound. Since the PC did not respond at all, I switched off (Using the button to switch on). When I tried to turn it on again, "nothing" happened. I can't even get to the BIOS. 
Only the fans (also the CPU and GPU fan) are running, the HDD is also running I think. 
The "CPU_LED" on the mainboard lights up red for about 15 seconds, then the "DRAM_LED" lights up for about 17 seconds. After that the CPU_LED lights up again ... 

 

Does anyone have an idea where the problem could be or how I can find out?

 

The PC is about 3,5 years old

System Specs:

Asus Z170-A Intel Z170 So.1151 Dual Channel DDR4 ATX Retail

16GB G.Skill Aegis DDR4-3000 DIMM CL16 Dual Kit

700 Watt be quiet! Pure Power 10 CM Modular 80+ Silver

Intel Core i5 7600K 4x 3.80GHz So.1151 WOF

6GB Asus GeForce GTX 1060 Advanced Aktiv PCIe 3.0 x16

a SSD and a HDD

Windows10 64 bit

[Nogrod]

I checked the RAM modules, one of the modules is broken