Update on the Acer. Arrived home from work last night and just for !!!!s and grins I decided to hit the power button on the Acer. Presto, chango... it powered up. In between tinkering with the insides the night before and last night I had do nothing else to it.
Sat down in front of it and proceeded to do a little investigation via the 'Event Viewer'. Lots and lots of entries related to 'kernel power down' i.e., sleep.
With that in mind I modified everything possible to preclude the laptop from ever going to sleep again. Also did a bunch of Windows Updates as well.
This morning it powered up just fine but not from sleep: from a shutdown which I did last night.
So, it appears to me this is NOT a motherboard issue but the infamous Windows 7 sleep problem. Which I've mitigated by never allowing the Acer to sleep again! (Poor bast**d)