sleep light indicator not working

Hi, i recently updated my 2011 macbook pro and now the sleep light indicator isnt working when i close the lid, it used to respond but it just doesnt do anything now. i should add everything else is working normal.

The only other thing i have added recently is install a carbon fiber skin? is there a sensor anywhere that the skin is blocking?

i tried resetting the SMC but i dont know if i am doing it right, should i get any reaction from the mbp?

its doing my head in at the moment as i just dont know how it can randomly stop.

 

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I'm not that bothered with the light it's self. I'm more worried that it could be a sign of something more serious.