What you try to do is to test different components on your system like power supply, memory, video card, etc
Remember that on a non-booting system, the only way to determine the failing part (processor or motherboard) is by testing them both on separate systems.
Also you can try to test all the components in a different system and make sure that every part is working fine. The most important parts to test are the processor, the motherboard and the system memory. (Please write down the model of the testing hardware).
Please refer to the following website for more information:
Also you can check