My modem, which I am using now, has a weird problem. It connects just fine, but there is no audio. So I dont hear the dialtone or connecting tones. It's a US Robotics 56K model 5686 V.92. However, on occasion it will suddenly make sound (volume is on high). but that lasts a few seconds and it goes silent again.
I can live without the sound, but I am used to it working on my other identical modem, and if I dont hear it, I am not sure if it's connecting. (My ISP tends to be "sleeping" every so often, so I have to dial several times to wake it up). So, that sound helps me know what's going on.
I removed the board from the case and connected it to thge computer. I found that if I apply a fairly strong downward pressure with my fingers on the potentiometer shaft, I do get sound.
I have another identical DEAD modem. I am thinking of taking the pot out of that one and swapping them. yea, I already used deoxit and put the soldering iron on the pot terminals, so it's obvious the pot itself is bad.
I'm posting this because I am a little leary to do this. This is the sort of stuff I dont normally work on. It's all surface mounted parts on both sides of the board, and so frikkin small I can barely see the solder joints even with a magnifying glass.
Since this board has traces on both sides, do I need to get the solder all the way thru the board? I've even heard of some boards having traces inside the board itself, so I guess they are laminated.
How anyone can work on this sort of thing is beyond me. I guess thats why people throw them in the trash and buy a new one. To even solder some of the tiny parts on it, would need a soldering iron tip about as thick as a sewing needle.
Fortunately this pot is on the edge of the board and has bigger terminals than most ot the other components, but it's still very small. I'd rather not risk killing the modem entirely, but I will replace the pot if I'm not dealing with a multi layered trace board.
Side note, I could probably remove the pot and just solder a resistor in place. I normally have them set at half volume and never change it once it's set.