I need instructions

[mowermel]

Hello All,

I am new to this forum and have a question about these modular "smart" power supplies.  I have built computers for 15 or 20 years but have not been using modular power supplies. This is the second modular PS I have gotten in under a year. The first one did exactly the same as this one: I build the whole box, carefully doing cable management and ensuring proper and complete connections for each installed cable. When I plug in the main power cord to 120v supply it does nothing at all. Literally nothing just as if I have not connected to power at all. In my earlier years I would tear down the PS and find the fuse that had blown then replace it. This is a brand new unit and the second time for exactly the same symptoms but about a year apart. The last one that did this I went and purchased a non modular unit then installed it. This time I am wondering if I have missed something and just don't realize it.  System= MSI X370 titamium MB, Radeon RX570 Aorus Graphics card by Gigabyte, AMD Ryzen CPU, M.2 HDD (1TB), 16GB DDR4 Mem, liquid cooling. Power supply is a Thermaltake toughpower grand series RGB 850.

Since this is the second time this has happened to me I tend to think I am not understanding some particular about setup/installation. Is there some minor/major detail that I might not know about modular power supplies. It seems hard to believe that I actually got 2 brand new PSs from different manufacturers that were failed out of the box. To me is seems more likely I have not learned something specific about them. I would read the manual and follow instructions but neither of them came with it. Watching videos online was no help either.  Got any ideas? Open to all commentary but please keep the denigrating stuff to a minimum.

[Darren YangTt Spm]

hi,

we think probably it's not power supply issue because you already changed two PSU

therefore, it might be the issue with motherboard, CPU, or RAM

so I will suggest you change the other stuff first