French door dropping and hinge adjust lock question

[mat_rew]

One side of my French doors is sagging, I checked online for possible solutions and the most obvious seems to be readjusting the hinges however only the top and bottom hinges have allen key slots for locking the height adjust, all three (top, middle , bottom) have the allen key slots for (presumably) adjusting height. Has anyone else dealt with something similar to this? 

[gaz_moose]

are the height adjusters not on the top and bottom of the hinge under plastic caps? are the hinges loose on the frame if you grab and rock the door?

[mat_rew]

@gaz_moose 

 

There are Allen key slots under the plastic caps on all three, I presume all three are for height adjustment, it's just that the guides I have seen advise adjusting all of the height adjustment Allen key slots so load is equally shared between the hinges and well I am not not sure if all three are height adjustment and also only the top and bottom hinges have this secondary Allen key slot which is normally for locking the height adjust. So, not sure if all three slots under the cap are height adjustment and if me changing the middle one to equal the load won't damage it if the locking wasn't there because it was broken or the slot under the cap for the middles was for something else like moving it forward or backward. 

[dpmiller]

are the grub screws on the sides not for locking the pivot, which is eccentric and adjusts the clamping?

[mat_rew]

@dpmiller

Do you mean the one I labelled as "locking (?) Allen key slot" for the top one, that feature exists for top and bottom hinges but doesn't exist for middle hinge; this is one the main questions I have since I don't know if it's not there to signify that the middle hinge Allen key slot behind the cap is for adjusting something else or its just how the middle hinge was built or if something is lost or broken for the middle hinge (and if so if adjusting the middle hinge to even the load when I am adjusting the hinges to lift the French door would create more problems)