Just some idle thoughts on the issue at hand.
Eletrically, conductors will still conduct. 40 years of exposure, well, who can be sure.
Mechanically, connections would likely be loosened with the temperature extremes. That being said, These things are deliberately designed to survive. Look at voyager 1 and 2, or Pioneer, or Surveyer.
Environmentally, unknown. The expectation was that the cheapy flags would have long since disintegrated, but they are still there as their shadows attest.
Finally, when the LM took off from the lunar surface, explosive bolts were used. Anything explosive will be causing collateral damage.
If you wish to consider whether one could simply go and turn on the remaining descent stage, well, no, not a chance. It is not even that it cannot. It's that it was designed to be abandoned on the Lunar surface.
ETA: I have no issue speculating about the current condition of the various Descent modules, But I can guarantee you none are flight ready.