Sudden long booting and weird BIOS ERROR code pattern.

[Z3br4]

Hello LTT Forum, I need your help.
For the last 2 days, my pc when booting started spitting lots of random beeps, without any reasonable pattern. I haven't plugged any new devices, even unplugging additional USB drives and devices that pc was handling good while booting didn't help. Sadly it's on cheap chinese LGA2011 motherboard.
It's running on American Megatrends chip (as far as i know) and bios version just says.. X79GA00E.

By doing my own testing 2/10 start up's were normal (few beeps and boot to windows after 3 seconds), the rest had inconcistent pattern of beeps, and either not boot to windows entirely, or boot after minute. 
Please help me decode those beeps
 13-7-1-3 (2s break) 10-1-33-2-2
During all this beeping, on screen was (in corner) B4 (Other codes i seen since built, so i know they are normal, but i can include the video on demand)
Specs:
OS: Windows 10 Professional 64bit;
Motherboard: Atermiter X79-G X79
CPU: Intel(R) Xeon(R) CPU E5-1650 v2
GPU: AMD Radeon Sapphire RX 570 Nitro+ 4GB
Memory: RAM: Samsung 16GB 4Rx4 PC3L-8500R M393B2K70CM0 -YF8 12M 
ROM: Crucial 1TB 2,5" SATA SSD MX500

PSU: SilentiumPC Elementum E2 550W 80 Plus

(i included mp3 file of those beeps with isolated fan noise)
And i'm sorry for any language mistakes, i'm not native to english.

BIOS_ERROR_CODES.mp3