All 3 passenger doors will not open from the outside, opens fine from inside on 1993 Pontiac Trans Sport

We've lubed everything and still can't get the doors open, any suggestion as to what part of the door handle we need to take a look at? Sliding door is the only door that will open from the outside.

Did they all stop working at the same time?Power locks ?
1 more answer
You will need to remove the trim panels from the doors and see if the linkage is working. There are small plastic clips that attach the linkage and on this old of a vehicle, my guess is they are broken.