Second hand iMac, missing screws and chasis ground
My brother bought a used 27” iMac mid 2011 in working conditions. The previous owner removed the hard drive to keep his information. When I opened it to install a new one, I noticed that the logic board had almost all it screws missing and had only one screw securing it in place. Beside this I put the HDD and it works ok. Now my brother told me that the USB ports were not working and does not turn on. I opened it and noticed when I turn the iMac on, the CPU fan spins and stops continuously; removed the power supply and found some burned capacitors. I decided to replace the logic board alongside the power supply and the same issue persist, the CPU fan turns on and off continuously and only the first light of the four diagnostic LED’s on the logic board is lit. My question is: does the missing screws on this iMac had to do something with it? Will this be a ground issue? Am I missing something? I really want to fix this iMac for my brother, he has visual problems and I’m sure this iMac will be a good piece of assistive technology for him.
Thanks in advance for all the help.
Is this a good question?