I'm new to the list but have a question. The front passenger side door on my 1990 Camrywon't unlock. Using the key or one of the switches the solenoid tries to "pop" the button up,butit stays down and the door stays locked. In fact even with pliers the manual lock button cannot be pulled up. The other door locks work normally, electrically and manually. With the door shut I can't figure out how to getaccess tothe locking mechanism, other than by cutting into the interior or outer panel. It feels like something has gone "over center". Suggestions?

 

I think if you take the door panel off and look inside, you will find a metal rod that has either come loose or broken somehow. You are gonna have to get inside the guts of the door to do this - if you cannot get the door open at all this is obviously going to be a big problem!
You may want to remove the drivers seat to make more room, i am not sure if you can get this inside panel off if you cannot open the door...but onceyou get inside there the fix will probably be obvious. If you are not sure what you are looking at inside there, just take the panel off the other door to look at how it works.