OK, an old thread but maybe useful to someone...

Not a bad idea to act on symptoms early. Got a M800 that flamed.
Thinking that the 12V voltage regulator exploded melting the MOLEX
connector behind and toasting the resistor in front. The main fuse
survived(!) Next step is to work out the culprit downstream. Approx
40ohms betwen yellow 12V supply and chassis so will pull out cards
until the low resistance path is found. Think the unit is a V2, any
reliable sources of used replacement boards?

Went for the XP ECM60UT31 (60W) over the 40W in part due to the 12V/3A
over 12V/2A. The kit is smaller than the OEM so maybe some minor drilling
etc... needed