i have a hp compaq nx6310 which has just had a new keyboard fitted and since then my speakers won't work but when I plug a headset in the sound works through them, why won't my speakers wrk but my headphone jack does??
When you plug in a headset two things happen. 1. a prong is bent back so that the laptop speakers are disconnected and 2. the headset is connected to the audio signal. When you un-plug the headset the the prong springs back and reestablishes the speaker connection. A number of people blame Ipod headsets for having plugs that are longer than standard and damaging the prong so that it can't spring back. Some people report that rapidly removing the headset plug has fixed the problem.
It is possible that the speaker wires were damaged during the keyboard replacement since they are very thin and may be exposed during the laptop disassembly.