Head scratcher PC boot problem

[StaticMA]

I have had some problems with my PC recently. When I tried to turn it on, absolutely nothing happens, no fans, lights, or anything.

 

I took some of my parts to a local PC repair shop and he tested my motherboard, cpu, ram, and power supply. At his shop, it booted and ran fine.

 

I take the parts back home, reassemble them and still nothing happening when I try to boot. The only parts that weren’t tested were the GPU, and SSD/HDD, and I guess the case.

 

Even if the GPU or a hard drive was the problem, the pc should still boot and give some sort of an error code right? 
 

I have tried booting outside of the case (I’m pretty sure I did not have the GPU in when I did that) and still no boot. I have also tested it at another location so that rules out it being a problem with my house’s electric.

 

I’m really confused about the whole thing so any feedback is greatly appreciated.

Thanks.

[SupaKomputa]

16 minutes ago, StaticMA said:

At his shop, it booted and ran fine.

Why not build it at the shop? What's the point taking it there?

[StaticMA]

59 minutes ago, SupaKomputa said:

Why not build it at the shop? What's the point taking it there?

I’m at college and I don’t have any original packaging for my components with me so transporting them all is difficult. I also have experience building PC’s so I was confident I could do it myself but maybe I’m just making a bonehead mistake. I’ll probably take it back to the shop if I can’t figure it out by the weekend.

[SupaKomputa]

45 minutes ago, StaticMA said:

so transporting them all is difficult

Well you're not taking it with horses.

Just take it all in the case. No need to bring the packaging.

good luck.