Login to your miner's web interface and click "Miner Status".

Whats your chip temps?
To my experience this should stay under 65 degrees celcius.
Whats the numbers under the "HW" column?
These numbers fluctuate. Ideally should be zero. Over a period of 12 hours i see anything around 8 to 35 on some boards. One of my board goes around 200. Most of them are 0.
Do you see any "x"s under the "ASIC Status" Colums?
You might see this very rarely. If there are many present your chips are probably fried.