Why won't my computer boot up (frequent beeps, black screen and reboots)?

Question

Computers

After a long session of use, the computer was put into standby mode, after which it refused to turn on normally.
Motherboard: gigabyte ga-b75m-d3h (I don't remember the BIOS version, but Google tells me it's AMI). Of the expansion cards, only a network card with Wi-Fi support.
Symptoms: after pressing the power button, the monitor does not light up, frequent beeps are heard (I counted 49 in <20 seconds), after which the computer goes to reboot, and so on in a circle. Judging by the sound and indicators, the hard drive is active, the processor cooler is also working.
No changes were made to the hardware configuration, no problems with hardware were observed to this day.
Intentional changes were not made to the BIOS settings, but the computer was left for several hours at the disposal of another user under an oath not to climb further than SPORE.

Answer 1

Probably just RAM.
listen for pauses, aren't there between signals?