Originally Posted by SouthArk370Z

First thing to try is beating on the SLU - some ppl have had luck with a good whack with a fist, others have had to beat the crap out of it. Doesn't always work.
Next, try removing the SLU and push the locking pin to the fully retracted position. This may make the microswitches.
Lastly, disassemble the SLU, verify switch operation, and reassemble in fully retracted position.
If none of those three work, you will have to buy a new SLU.