Xbox one x beep but dont boot

hi, looking for help, I bought a one x on eBay for repair, looking for a hobby for this lockdown basically, however the console turns on and after like 5 sec shuts down, I opened and the first thing I realized was the connector of the front usb was damaged, the second was the fan didn’t work. everything ok so far, however I was from here things got weird. I tested the fan and was working, the hdd and dvd drive are working, the heat sink gets warm. apparently everything works as should, kind of, here where I was thrown off, I was able to put the fan working, if I press the board on one corner (between the power supply and hdd), to one of the directions, don’t work all the time, but I don’t want to force it for obvious reasons, and the other I saw, was from your videos, when you install a new or different power supply, you can turn it on immediately, mine cant, just beep and nothing else. i have to wait a bit so the light comes on. any idea what could be causing that kind of problems?