I plug my headphone into computer's sound card. The headphone only works when it is pulled out slightly. If it is fully inserted, some sound won't play as loud as it should be (human voice is noticeably weaker).
My speakers, and other headphone work well on the sound card.
Is this a compatibility problem, or my headphone is broken?
Headphone: Cosonic Digital Stereo Dynamic Headphones (MDR-CD850) with volume control
Thanks.