[SOLVED] PC Build: momentary powers on than shuts down, fans turn, no post.

[Clark_5]

I ordered the following parts from Amazon. PSU was defective and they replaced. I verified all voltages on replacement PSU. No change with new power supply. I also replaced Gigabyte motherboard. No change in condition. Tried all memory slots with single 16 gb stick, no change. Went thru check list by disconnecting all connections except 24 pin and cpu power, no change in condition. If there is a short, how would i trouble shoot it.
1 - EVGA 500 B1, 80+ BRONZE 500W Power Supply
1 - Intel Core i5-8400 Desktop Processor 6 Cores up to 4.0 GHz LGA 1151 300 Series 65W
2 - Ballistix Sport LT 16GB Kit (8GBx2) DDR4 3000 MT/s (PC4-24000) CL16 SR x8 DIMM 288-Pin Memory -
1 - GIGABYTE GA-Z270P-D3 LGA1151 Intel Z270 2-Way Crossfire ATX DDR4 Motherboard
Windows 10
500 my solid state drive

 

[PC Tailor]

Your motherboard is for 6th and 7th Gen Intel CPUs - your CPU is 8th Gen.
You need a new motherboard.

 

[Clark_5]

Your motherboard is for 6th and 7th Gen Intel CPUs - your CPU is 8th Gen.
You need a new motherboard.

How about changing CPU like i5-7500 or 6600. Won't that work?

 

[PC Tailor]

That's the other option yeah.
Apologies - just usually people are going to change the motherboard before the CPU. That and the 8400 is better than both of the ones you suggested in benchmarks and is later technology.