Question PC Boot Loops for a random time and then Starts

[Sammm_5405]

So my motherboard just got fried a week ago, and I gave it to a person who switched out some parts and now it works... but it takes anywhere from a minute to an hour just to POST. I press the power button, HDD led is turned on, fans spin, HDD led goes off and fans keep spinning for about 10 more seconds, then pc restarts the same process till my pc realizes it's enough torture for me and on a random boot loop it turns on normally. I have no performance issues whatsoever, everything's just fine. Just this startup problem is eating up my mind. Someone please help.

Pc specs :
i3 - 3220
Zebronics ZEB-H61 motherboard
2x4gb rams @ 1333 MHz (XMP not available due to mismatched sticks)
ASUS GT710 gddr5
512gb boot HDD + 1tb storage HDD
450W PSU

Btw, I already reset the bios, tried starting with only one stick of ram, without anything else connected to the motherboard.
I am clueless as to why this is happening and need some help.
Generally PCs either are stuck in boot loops or start normally, I haven't found a single thread on the internet regarding this problem.

I know its a hardware problem but I am not old enough to buy a new pc.

Could it be due to a silly mistake I've made in connecting something maybe?

 

[Sammm_5405]

Edit :
Also I forgot to mention - in the boot loop there is no display, it seems the motherboard itself isnit initiating