I have a customer called and said that their heat pump was not cooling. When I arrived I confirmed that there was a problem and unit was not cooling. I found everything was running even the compressor was running. I connected gauges to unit and found while compressor was running the high and low side pressures were equalized. This sounds to me like a bad or inefficient compressor. Is there any other thing or component could be bad in this unit that would cause the high and low pressure to be equalized while the compressor is running? Can anyone help me with this?