Please help, computer turns on and then off and repeats!

[YazZy444]

Hello, I am new to this site so hopefully i'm posting in the right place. Anyway my computer (I did not build it myself) which has been working fine since I had it, and had no issues yesterday only recently started having the fan speed up a bit for about 1 or 2 minutes upon start up and now today when I got home my pc instead of turning on would turn on for about a second and a half and then turn off and would repeat, even without me doing anything. I have no idea what to do at all about this so I am hoping people can help me as best they can, thank you for taking the time to read this and hopefully helping me.

Some extra details (dunno if they are needed) will be listed here
gtx 1050 ti
i5-8500
8 GB of RAM
H310M S2H motherboard
Windows 10 (standard)

I haven't really opened it up before so I honestly don't know what could be the problem, dust build up or overheating or some people say ram I honestly have no clue since I have never hit it or anything I just always left it as it is and cleaned the floor underneath it every so often, one of my friends suggested I might need to reset bios and I think explained how but I have never touched it so this is really confusing.

 

[rgd1101]

where did you buy from?
full system spec? include make and model of the psu
could be the psu.

 

[YazZy444]

where did you buy from?
full system spec? include make and model of the psu
could be the psu.

The seller/company is fierce PC, however I bought it on amazon

lets see adding to what I said before, the ram speed is 2666MHz, 1TB hard drive the actual brand of the psu is not listed however its 500 watt and the model is ATX-500b, so far this is what I was able to gather, sorry. I will try to find more but in the mean time I hope this helps

 

[rgd1101]

any prebuild that doesn't list the psu are usually cheap low end.
would change it or contact them

 

[YazZy444]

any prebuild that doesn't list the psu are usually cheap low end.
would change it or contact them

I see, I'll look into changing it but I'll have to wait for their reply since they put a warranty void if removed sticker on the panel of my pc so I cant open it and do anything without voiding my warranty sadly.