A Desktop PC built from off-the-shelf DIY parts, rather than a prebuilt from a major manufacturer. These can also be built by an SI using off-the-shelf parts.
Try using No ram , no 3v batt and onboard HDMI (or vga) from CPU if it has onboard graphics (the cpu). see if it beeps.
"Motherboard: AMD ASRockB450MPro4
PSU: ROSEWILL ARC550 80+ bronze
CPU: ryzen 7 5700G
GPU: Nvidia geforce gtx 1650
RAM: 2x 8gb DDR4 3600
I turn It on and everything lights up but get a black screen for around 30 seconds, then it turns off and immediately starts up by itself again, then repeats the process
No its not brand new"
P.S. These Ryzen CPU's seem to be notorious(for problems -like) sk.A reanacment.
When you say that "the computer was damaged during shipping", do you mean that you had bought the computer and it was damaged when it was being shipped to you?
1 
Hi
What is the make and model number of the motherboard?
What type of damage occurred?
How far into the start (POST or boot?) sequence does it get before it reboots?
Is this a brand new PC ?
jayeff さんによる
Did you try bios reset , -/+ 3v battery pin short? With no ram ,did the system beep?
ediflorianUS さんによる
Try using No ram , no 3v batt and onboard HDMI (or vga) from CPU if it has onboard graphics (the cpu). see if it beeps.
"Motherboard: AMD ASRockB450MPro4
PSU: ROSEWILL ARC550 80+ bronze
CPU: ryzen 7 5700G
GPU: Nvidia geforce gtx 1650
RAM: 2x 8gb DDR4 3600
I turn It on and everything lights up but get a black screen for around 30 seconds, then it turns off and immediately starts up by itself again, then repeats the process
No its not brand new"
P.S. These Ryzen CPU's seem to be notorious(for problems -like) sk.A reanacment.
Your bios has to be at least version P5.00 for CPU to be supported. https://www.asrock.com/mb/AMD/B450M%20Pr...
ediflorianUS さんによる
When you say that "the computer was damaged during shipping", do you mean that you had bought the computer and it was damaged when it was being shipped to you?
Jacob Mehnert さんによる