Kitchen downlights problem

[MikeyB1983]

Hey guys was wondering if anyone can help me, I was changing the bulbs in my mother-in-laws kitchen and saw that inside one of the 'pots' was black as it had been burning. What could the possible cause of this be, what sort of tests can I do to establish where/what the problem is??

Many thanks guys.

 

[Stroppy]

I prefer to call them lamp-bulbs to annoy both sides.