Need help repairing my Chi-Fi headset.

[shrewdgamer]

I have a Chi-Fi gaming headset, it has a USB connection, no 3.5mm connection, this USB cable goes into the left headphone. Some days ago it stopped producing sound from the right side, I opened it up and checked the internals, the left ear cup has a PCB, the right ear cup receives wires from the left side, all the wires are soldered, I used a line tester on the right side's soldering to see if it was receiving any input, and it was receiving some electricity as the line tester lit up but it still wasn't producing any sound in the right side.

Is there anything I can do, which might resolve this?

[Chuck H]

Well... I think the leads will be color coded. If you have a DMM you could test for continuity between the leads going from the left side to the right individually. There's probably an amp for each side on the board for stereo. So you could check that and if you identify both amps make sure they read the same for voltages. After that it's a short in the head strap between sides and I don't know a good way to fix that.

[shrewdgamer]

Well... I think the leads will be color coded. If you have a DMM you could test for continuity between the leads going from the left side to the right individually. There's probably an amp for each side on the board for stereo. So you could check that and if you identify both amps make sure they read the same for voltages. After that it's a short in the head strap between sides and I don't know a good way to fix that.

Thanks, I'll try it. Can you tell me what does an amp look like, does it look like capacitors or resistors. On the PCB I could only see traces and ICs.

[Chuck H]

Thanks, I'll try it. Can you tell me what does an amp look like, does it look like capacitors or resistors. On the PCB I could only see traces and ICs.

The at least one of the IC's is likely a dual transistor amp. An op amp. More likely there will be two, minimum. More if this is a mic headset. op amps usually have four pins on each side. Obviously I can't know the exact circumstances on your board for circuit or even exact function. Even with a schematic, in fact, since I'm not a tech and only do tube gear. But basic troubleshooting is what it is. The right and left sides will probably have similar amplification circuits. If you can locate that visibly or by comparing peripheral component values you can test circuit voltages to see if one is behaving differently (ie: no voltage on pin "X") than the other.

More likely is a fault in the wiring. An open circuit. If this is in an accessible location maybe it can be fixed. If it's in the head strap area, the cord itself or within a molded plug case then it may not be readily accessible. This is, unfortunately, my most common experience with headphones.

[shrewdgamer]

The at least one of the IC's is likely a dual transistor amp. An op amp. More likely there will be two, minimum. More if this is a mic headset. op amps usually have four pins on each side. Obviously I can't know the exact circumstances on your board for circuit or even exact function. Even with a schematic, in fact, since I'm not a tech and only do tube gear. But basic troubleshooting is what it is. The right and left sides will probably have similar amplification circuits. If you can locate that visibly or by comparing peripheral component values you can test circuit voltages to see if one is behaving differently (ie: no voltage on pin "X") than the other.

More likely is a fault in the wiring. An open circuit. If this is in an accessible location maybe it can be fixed. If it's in the head strap area, the cord itself or within a molded plug case then it may not be readily accessible. This is, unfortunately, my most common experience with headphones.

Sorry I forgot, there are two things which look like capacitors. Photo below. The wires going into the right side are grouped in a tube like thing, I don't think it will be easy to repair a break in those wires, there are at least six wires going into the right side, two for driver, two for LED and another two for another LED. Do you think I can use DMM on those capacitor like things? Can they die, how do I check? Can I desolder them and replace them? Thanks

[dmartn149]

More likely is a fault in the wiring. An open circuit. If this is in an accessible location maybe it can be fixed. If it's in the head strap area, the cord itself or within a molded plug case then it may not be readily accessible. This is, unfortunately, my most common experience with headphones.

Chuck's right. The most likely fault is the wiring, not the pcb or any of it's components.

[g1]

The troubleshooting in the first post made me think it's the actual speaker in the right side that is bad.
Receiving signal, no sound.
Have you tried measuring resistance at the right speaker terminals? You will need to disconnect one of the 2 wires going to it, doesn't matter which one.

[dmartn149]

Ive had a couple of headsets develop intermittent breaks at the in line cable control. I don't use those so I just cut them out and re-splice.

[shrewdgamer]

Chuck's right. The most likely fault is the wiring, not the pcb or any of it's components.

It'll be difficult to repair, if it's the wire, because 6 wires are grouped in.

The troubleshooting in the first post made me think it's the actual speaker in the right side that is bad.
Receiving signal, no sound.
Have you tried measuring resistance at the right speaker terminals? You will need to disconnect one of the 2 wires going to it, doesn't matter which one.

Thanks, I'll try this. I haven't measured resistance a the speaker terminals, what should I do after disconnecting one wire?

Ive had a couple of headsets develop intermittent breaks at the in line cable control. I don't use those so I just cut them out and re-splice.
[ATTACH=CONFIG]56201[/ATTACH]

This one doesn't have in-line cable control, it has a volume control behind the left headphone, you can see it as a disk on the PCB in the attached image.

One of the capacitor like thing has a blackness near it's joints, does it mean it shorted?

[g1]

Thanks, I'll try this. I haven't measured resistance a the speaker terminals, what should I do after disconnecting one wire?

Set your meter to resistance. Put one probe on each speaker terminal, + and - doesn't matter for this. Resistance should probably measure somewhere in the 8 to 40 ohms range. If necessary do the same on the good side and compare the 2 readings.

[shrewdgamer]

Set your meter to resistance. Put one probe on each speaker terminal, + and - doesn't matter for this. Resistance should probably measure somewhere in the 8 to 40 ohms range. If necessary do the same on the good side and compare the 2 readings.

Thanks for this information. I'll try what you suggested. Before that:

Could the blackness near one of the joints of the capacitors, the place where it shows C4, indicate that capacitor died or it's joint is damaged? Could it cause the problem, if it is responsible for the right side?

[Chuck H]

It may. Though not necessarily a component failure. It could be that some oxide is present more so than the other joints. I don't know what solder was used on that board, but it's probably rohs compliant.?. That could mean silver, which oxidized black. But the joint doesn't look bad otherwise and the color of that joint is no indication of a component failure in my experience. The component itself would most likely show visible signs of failure before the solder joint was affected by anything that would fail the component. If you get my meaning.

How are the continuity tests going?

[shrewdgamer]

It may. Though not necessarily a component failure. It could be that some oxide is present more so than the other joints. I don't know what solder was used on that board, but it's probably rohs compliant.?. That could mean silver, which oxidized black. But the joint doesn't look bad otherwise and the color of that joint is no indication of a component failure in my experience. The component itself would most likely show visible signs of failure before the solder joint was affected by anything that would fail the component. If you get my meaning.

How are the continuity tests going?

Sorry for the delayed reply. I forgot my password and I was unable to reset it.

Does the soldering iron always has to be connected to the power or can I disconnect after heating and immediately melt the solder? Thanks

[Chuck H]

Sorry for the delayed reply. I forgot my password and I was unable to reset it.

Does the soldering iron always has to be connected to the power or can I disconnect after heating and immediately melt the solder? Thanks

I have to guess you've already tried this... And failed I've had no luck with such stunts. Though I did once manage a field repair with a nail. I gripped it with a plier and heated the end to red hot and quickly re-melted a bad joint on a capacitor. The amp got me through practice but I re-flowed the joint proper when I hot it home. You really do need consistent and steady heat to flow a solder joint.

Are the headphones bolted high up on a wall or something? Soldering iron doesn't fit extension cords?