I have in fact traced at least one motherboard fault.
This lies with a Dual FET driver package, namely a NIKO-SEM P07D03LV.
I have visually inspected the package and found the surface pitted.
This pitting is consistent with package burnout and is entirely consistent
with one of the FET drivers in the package having gone to meet its maker
in the sky!
Further research has detailed a similar failure with this device on a MSI
board and how, perhaps this device is used to set the RAM or AGP specification.
Note !!! - albeit in French - I'll get back to you with the translsation later.
see - http://www.nokytech.net/forum/showthread.php?t=85432
In attempt to factor in the genesis of the fault in the first instance, so far
as I contend the possibilty of RAM setup type to 200MHz is not possible
on this board but can be configured by jumper, it may be the root cause
of the device failure. Note even so, this is presently not a certainty.
So far as the package has generally application in the DC-DC, power
management and disconnect switches at least that is, according to an
equivalent - its a starting point for a failure hypothesis.
The smell/odour as noted was probably the epoxy package of the device frying and/or a nearby
reservoir capacitor getting its electrolyte cooked. The cap after power off was warm to touch.
Any comments/insight greatly appreciated