Dell OptiPlex 7020 SFF Intel Core i7-4770, 16 GB RAM DDR3, 240 GB SSD,

I tried to refurbish another pc by taking the motherboard from this pc, but it didn't work so I put the motherboard back in. To my knowledge rhe individual parts such as the cpu, the cooler, the ssd and the 2x 8gb ram work however the computer wouldn't start up. It would just make a lot of noise and not connect to the monitor (before hand the pc was really quiet). May be due to me breaking something or messing up a wire. note: individual parts most likely work however I couldn't get the pc to start up

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