Asrock B450 pro4 not coming on in my house

Good day good people. Please I needed your help with my desktop. A computer technician built a pc for me based on my specifications which are:
AMD Ryzen 5 3400g
AsRock b450 Pro 4 motherboard
Adata 4gb ram and Ballistix 4gb ram
ZSseries 650w psu
128gb ssd and 1 tb hdd

When he delivered it to me 3 weeks ago, it was working perfectly up until 2 days ago when I put it to sleep and went to sleep myself. I woke up the next day and turned it on, nothing. No power any where except one of the lights on the fan. Amd fan was off and no case fans came on. I tried another cord and same thing no power. I called in the technician and he brought with him another power supply (corsair 1000w) and another power cord. It did not come on despite testing with another psu. So he took it back to his work place to have a look at it thoroughly. He called m and told me it came on in its work place and that he did not do anything. He sent me pictures of the pc working well and booting into desktop where I saw my desktop picture so all was OK. He brought it back to my home yesterday and again it didn't come on. Nothing. Tried with two different UPS and nothing @ all. All other home appliances are working perfectly. Is there something wrong with my board for it not to work in my home? Thank you. I really need advice on what to do...

I see you listed your location is Nigeria, having lived and worked in Africa I
have to ask, is your power low at your home at the moment? I know in several countries I have worked in in Africa it was common for people to get as low as
150v instead of 220v. You mentioned UPSes but if they are under powered it
would still be an issue. You need at least a 650w UPS for your system, I am
assuming you connect all your powered peripherals to it too.

If you have multiple UPSes then try connecting a UPS (the most powerful one you
have) to just the PC and use another one to power any other peripherals display, printers, scanners etc).   

When a power transformer is overloaded it will often output voltage bellow it's
operating specifications so if it has been particularly hot in your area (for
example) and people have been heavily using ACs it could explain low power. If
your UPS has been forced to compensate for this low power for a prolonged
period of time it will have drained it's battery. These are just theories but
generally speaking, if a system works in one place but not another there is a
power issue at the location it will not work.

Good luck

Check your power in your house, if you are running under voltage that will
cause the issue you are experiencing. A lot of electronics will continue to run
on low voltage (including PCs) but a UPS is designed to keep power at rated
spec. This means that the UPS will draw power from it's battery to supplement
low power. Just like when a UPS turns off after a power outage when the battery
is drained it will do the same if the battery is drained and you have low
power. It may allow low wattage devices to work but when it senses a load
beyond what it is able to provide it will not send power to that device. In all
likelihood your PC will power on if you connect it without the UPS unless your
PSU specifically has a low power protection. Most quality PSUs are switching
models that are able to handle voltage from 110v (US standard) to 260v and
quite a bit in between. I wouldn't recommend using your system without a UPS if
you have bad power but connecting it just to test for a brief period should be
fine.

If your power is indeed low then you will need to contact your power company
and report the issue.

As I said, some PSUs will have low voltage protections that will prevent them
from coming on if power is low and there is a load attached to them. I have had
power supplies come on with the paperclip trick yet fail to come on when
connected to a system, they were dead.

Your options are pretty simple:
Test your voltage from the wall (or have an electrician do it to be safe).
Try a different, new PSU, your current one could have an issue.

Your symptoms do not align with a faulty motherboard, issues like this are
almost always power related, either with the supply from the wall or from the
PSU itself. Stay calm and don't panic, we (the forum community) will help you
get the issue resolved

Let us know the results of the suggestions I made and good luck

Apologies, I meant to write *No Low Voltage* detected...