Awesome thanks for posting - going to do this pretty soon....since it is almost time to switch my system manually back to heat for the winter! Thanks for the fix!

Completed the fix this past weekend - got the panel out and soldered all in few minutes time... the 3 cold solder joints indeed had failed, they barely had enough solder on them... all fixed up and working great know, visually verified by watching the air-mixer control arms under the dash work step by step as the temp knob was turned...(or you can verify operation by holding the power button with scan up buttons, and then sweep the temp control knob).
Awesome.