Hi all
I was experimenting a circuit I have built (infrared headphones). I used the headphones jack of my laptop as the source of the audio signal for the transmitter circuit. One of the jack lines is the ground, and is connected to the transmitter ground, the supply voltage of the circuit is a 9V battery. Accidentally, the audio signal line from the headphones jack was connected to the +9V and for several seconds. the wires and the plug became hot, and the laptop sound stopped. I disconnected everything and tried the laptop sound.. even the volume was max. but it wasn't working, no sound. After I restarted the computer, the sound worked! but it wasn't high as usual, the volume was about 1/3 the volume was before. I checked the 'software' issues related to volume and sound device... everything is as normal. When the volume is 100 it's actually low as it's about 30~40.
At the beginning I thought it would be a burned resistor near the headphone jack, and it stills a possibility. I found a pdf for the laptop circuits you can download it from here: http://www.eserviceinfo.com/download.php?fileid=44467
In page 26 there are the sound related circuits. Actually I didn't understand them good due to some namings I don't know....
Any suggestion/idea is appreciated.
Hazim
I was experimenting a circuit I have built (infrared headphones). I used the headphones jack of my laptop as the source of the audio signal for the transmitter circuit. One of the jack lines is the ground, and is connected to the transmitter ground, the supply voltage of the circuit is a 9V battery. Accidentally, the audio signal line from the headphones jack was connected to the +9V and for several seconds. the wires and the plug became hot, and the laptop sound stopped. I disconnected everything and tried the laptop sound.. even the volume was max. but it wasn't working, no sound. After I restarted the computer, the sound worked! but it wasn't high as usual, the volume was about 1/3 the volume was before. I checked the 'software' issues related to volume and sound device... everything is as normal. When the volume is 100 it's actually low as it's about 30~40.
At the beginning I thought it would be a burned resistor near the headphone jack, and it stills a possibility. I found a pdf for the laptop circuits you can download it from here: http://www.eserviceinfo.com/download.php?fileid=44467
In page 26 there are the sound related circuits. Actually I didn't understand them good due to some namings I don't know....
Any suggestion/idea is appreciated.
Hazim