Unable to boot Dell XPS 420 after replacing motherboard and PSU

[Wave]

Well I am having Dell XPS 420 from past couple of days. I have noticed the system of mine did not seems to booting at all. I am unable to figure out whether this particular issue is associated with the power supply or due to any other hard ware issue. Let me know if you are having any specific solution to get the requirement of mine. any help would be highly appreciated. Thanks a lot in advance.

[Alexisus]

If the motherboard is having 8 pins and power supply is having 4 pins you have to use the 4 pin connectors. By default 4 pins connector can be placed on the 4 pins located to the CPU which you have placed on the computer. If there is cover over the 4 pins of the 8 pins connector then you have to remove the same you have to put the power supply on the same. So you should try the same and let me know whether it is working or not.

[Nutty]

Let me know whether you have installed standoffs under the motherboard? If you have not placed the same then you have to align the screw holes on the motherboard . if you have no placed any extra standofss touching the motherboard or you have placed the same at the wrong place then it might cause short and prevent yours computer to boot. You have to see that you have placed the Standofss on the computer of yours.

[AmdUser]

I recommend that you should boot your computer by placing the RAM individually on the system of yours. if your system is booting then you have to manually check the speed of the RAM and timing as well as voltage to the manufacturer specs in to the BIOS before you try to boot the computer of yours. by default all the standard RAM voltage is 1.8v for DDR2 & 1.5v for DDR3. If the RAM of you is rated to run than that of the standard voltage then motherboard has underlock the RAM for the because of the compatibility issue.

[Logan.M]

You have to see that the CPU fan should be plugged properly on the motherboard. Well I let you know that the some of the motherboards would not boot at all if the CPU fan are not detected so that it can prevent the burning up of the CPU which you have installed. SO you have to see that the CPU fan is plugged and working properly. If there is an issue then you should change the port and see whether it is working or not.

[Abhibhava]

Well the computer components are very sensitive for the static electricity. It would take very low voltage which you will be able to feel can damage the components of the device. You have to implement something which would reduce the chances of the damaging component. You should also include the wearing an anti static wrist strap. You should also avoid to built the computer on the carpet. Working on the smooth surface would be the ideal solution for you.