Motherboard not working black screen and usb not working?

Question

motherboards

In general, hello, dear friends.
I bought a motherboard from a swindler, a scammer. Biostar TB250-BTC has arrived for mining. The seller (fraudster) says that the board is new. She arrived, in fact, without a battery. After 10 days, I bought an Intel Pentium g4400 processor and 4gb ddr4 patriot RAM.
Since it was indicated above that it arrived without a battery, I inserted it as a new battery into this motherboard, installed RAM, a processor, and so on. I turn it on - and HOP HEY ALALEY - a black screen and that's it. I connected the keyboard and mouse - for some reason they did not turn on at startup. Could the problem be with usb? The coolers on the board work, but the black screen is all.
If someone talks about the processor and RAM, then the master checked the processor, as if it was working. And RAM too. He says it seems to be in the motherboard.
As a result, the master looked for a problem in this motherboard and did not find it, he said, just take it away, I don’t know what’s wrong with it. Although I doubt that he checked it at all, since he got a lot of work, and laziness can bathe with my board ...

In general, help. The scammer says that it is new and works, but I doubt it very much .. Help, please, I will be grateful.

I noticed one more thing, but when you turn it on, the board works for 5-10 seconds, then it reboots and works fine

Answer 1

Connect the beeper (speaker) to the MP and listen to its beep, then google what the specific number and length of beeps means.

Answer 2

Look for the diagnostic POST board. There are several options. Which one is more convenient. Well, in general, if a cyclic restart, something with power most likely. Shim may have flown. Unmy electronics engineer could quickly check. I used to have a lot of such boards, I gave them to a friend, he repaired them, now we live in Moscow and we don’t communicate =))