Recheck all your Connections on the Motherboard and on the Power Supply Side.

Remove all connections between Case & the MB - Does it Boot ?
 
unplug All external devices - even KB & mouse - does it Boot ?

Thanks to all who have made suggestions here.  I've tried them all (some a second time, since I'd already tried them once).  Unfortunately we have no joy.  The second post in the same thread that Sajin suggested, on the I/O shield shorting out to the inside of a USB port, says that if the 5VSB power light is flashing, this is a sign of bad power, and the PSU should be replaced.  Since that post is from EVGA tech staff, I give it a lot of weight.  Mine is blinking.  Is that generally agreed to be a sign of a shot PSU?  If so, yippee, they're easier to replace. 
 
bcavanaugh, thanks for your service.  I was RA too, three years, Vietnam era but duty entirely stateside.
 
Sajin, great pointer to an obscure problem, and I'm sorry to say it's not the issue here.
 
Cool GTX, great suggestion.  I had tried it with all external devices and all add-in cards removed, but not without the front panel connectors.  Unfortunately, no change.  Right after ATX became a thing, I had a system that would periodically crash without warning.  I replaced every piece of that sucker and still it crashed, until I finally replaced the one thing it couldn't possibly be, the case.  And that was the fix.  Unfortunately, jumping the power pins didn't do the job here, but thanks all the same.
 
Thanks to all.

Sajin,
 
Thanks for the advice.  I'll get a new PSU and will update after I try that out. 
 
 

Interestingly my 8700k just died on a z370 FTW board the other morning. I have extra parts laying around and was able to deduce that it is definitely the CPU. Tested with a G5500.
 
Yours sounds like a PSU issue, because you're not getting any life out of it, but mine would light up and spin fans, but give post code FF. Changing CPU will let me boot.
 
Good luck.

My new PSU arrived last night and is installed.   That was the issue.  I now get successful POST and it begins the OS load.  I'm running Win 7 Pro on this and I've got to remember how I tweaked the BIOS settings for Win 7 (it currently hangs on OS load on a reboot, but will successfully load OS from a cold boot).  FWIW, the new PSU is an EVGA 650w Supernova G2 Gold.
 
I really appreciate everyone's guidance and suggestions.  Thanks to all for your help. 

jmack254
My new PSU arrived last night and is installed.   That was the issue.  I now get successful POST and it begins the OS load.  I'm running Win 7 Pro on this and I've got to remember how I tweaked the BIOS settings for Win 7 (it currently hangs on OS load on a reboot, but will successfully load OS from a cold boot).  FWIW, the new PSU is an EVGA 650w Supernova G2 Gold.
 
I really appreciate everyone's guidance and suggestions.  Thanks to all for your help. 

 

jmack254
Satchmo0016,
 
I'm sorry to hear your 8700K died.  I've never heard of an in-place CPU dying unless it was overclocked or overheated beyond spec, and I'm assuming yours wasn't.  I'm an IT manager and have been responsible for about 12,000 cpu/years of system time, and that's a first.  I hope this isn't a bad omen for my 8700K.  It's really a nice chip.
 
By the way, nice screen name.  It's a Wonderful World, is it not?

Yeah it's quite the anomaly. It was delidded for about 6 months prior and when I took it apart after it failed, it looked perfect. So I know it wasn't the delid. I believe it was either the IMC on it died or there must have been some slightly uneven mounting pressure from my waterblock. When delidded the die is slightly closer to the IHS and that could make it more susceptible to damage from uneven mounting pressure combined with heat cycling. The PCB is also pretty thin on 8th gen so that doesn't help it's durability. It didn't die on it's own though, CPUs just statistically don't die like that.

Ahh yeah, nobody ever knows of ol satch. Played the horn for a long time but haven't in about 8 years... Been meaning to pick it back up!