Another odd problem to resolve! ....here's the current situation:
Ryzen 2600 with broken VCC pin / Ryzen 2300X no damage - both known working in other systems
Wraith Stealth Cooler
Gigabyte A320M-H motherboard - brand new sealed, but bought 2nd hand (box says Ryzen 3000 ready)
Corsair LPX 2x4Gb DDR4 3000 / 2x 8Gb Generic DDR4 2666
Seasonic Focus Gold 550W / Old (known working) Corsair VX450 from my old PC
HD 6450 1Gb GPU
480Gb NVME SSD
So I built the system but no storage drive, the 2600, Seasonic PSU. System shows no signs of life - nothing to indicate power. I try the following to remedy it:
Reset CMOS
Replace battery
Switch to 2300X CPU
Both RAM, no RAM, 1 RAM only, either slot (was using Corsair modules)
Switch PSU to VX450
Remove GPU
Short the power pins on the motherboard directly (bypass the power button in case it's faulty)
Nothing works.
Next, I have a 2nd mobo/cpu/ram combo of an i5 6500, H170 and 16Gb DDR3L - I reuse the Seasonic PSU, Case and all associated cables. LED on the mobo lights up straight away, and the system boots when power button. Seems the PSU and ccase cables are fine. Given it doesn't work with or without RAM, or with either CPU I assume it's a power fault on the motherboard and order the exact same board off eBay to switch it out and try and rebuild the system again.
I've just rebuilt the system and again I'm having the exact same issue - zero evidence of power reaching the system. I tried all the same steps above, but no success again. It's made me wonder if the original motherboard was actually fine and the issue lies elsewhere.
Given I'm getting no response at all, even though the PSU has been proved to work and other elements of the build has previously worked, I'm at a bit of a loss what to do next. Anyone got any thoughts?