A week ago I had this issue after trying to change my ram (whether this triggered it or not, I don't know). Since then, as soon as I power the PC on (before windows or really even the harddisk begins spinning) a non-stop BZZZZZZ sound happens. This sound does not stop as long as the PC is running but changes in intensity as if a fan is spinning up super fast for no reason then slowing down. I cannot tell what is causing this, I just have a standard cpu fan and the fan in the PSU and I believe a fan on the GPU from what I know. There is constant sound like a fan speeding up then slowing then kind of sputtering as if it's having issues keeping up.
I cannot tell if this is something with the fan on the cpu, the psu fan, gpu fan or saomething else entirely, and don't really know how to narrow it down. From visuals, I cannot notice any issues with the fan on the CPU, can't really see the gpu one or psu one well.
If needed, here are my specs
4gb ddr3 ram
1 tb HDD WD Black
Win 7 Ultimate
I'm planning on just building an entirely new PC at the end of the month but for the time being this buzzing is maddening.