need help asap

so about two days ago my computer crashed and froze completely and wouldnt turn off till i unplugged it and yesterday when i was playing a game it did the same thing but this time it made a really loud buzzing sound out of the speakers and wouldnt turn off again so i unplugged it thinking it would work and then it wouldnt even turn on or anything so i left it alone for a bit now today it boots up but does not show any display my keyboard wont turn on neither will my mouse so i cant even access my bios to troubleshoot and i truly have no clue wtf happend its never so much as even lagged let alone this, to be fair it is a bit on the older side but it is a really good computer and iv never had any issues, i tried cleaning everything in it makeing sure nothing is loose all of that but nothing is working anyone know whats going on?