logitech C920 dead

[frozensun]

I purchased logitech C920 HD Pro webcam.

Owner said it has sound but no video.

I thought it's driver problem and I'll fix it cuz he had W7,but no luck even with W10

W10 recognizes the cam but it simply won't show picture.

I'm not inti electronics but I mean to webcam fail is very rare.

So what could be the reason not to work?

I'm not into electronics,but I'm willing to open it and see maybe for damage components though I don't know to test them with multimeter.

[Moonzy]

could be loose/broken wire(normally the core of wire)

or a burnt out IC

 

hard to say

[frozensun]

3 minutes ago, Moonzy said:

could be loose/broken wire(normally the core of wire)

or a burnt out IC

 

hard to say

is it repairable?U mean USB cable wire?But then PC wouldn't recognize the cam,right?

[Moonzy]

Just now, frozensun said:

is it repairable?

broken wire/core, yea

 

broken IC, probably just buy a new webcam

[WereCatf]

7 minutes ago, Moonzy said:

could be loose/broken wire(normally the core of wire)

or a burnt out IC

It's a USB 2.0 - camera, so there's only 4 wires, ie. +5V, GND, D+ and D-. If any of those wires was broken, it wouldn't work at all, so the issue is something else. Assuming OP doesn't have the tools or the skills to trace the PCB and replace SMD-components, the camera is unrepairable by OP.

[Moonzy]

1 minute ago, WereCatf said:

If any of those wires was broken

im thinking internal ribbon cable/wire

if it's a ribbon cable, it's pretty hard to fix though

[WereCatf]

Just now, Moonzy said:

im thinking internal ribbon cable/wire

There is no such a thing there:

[frozensun]

My friends if the cable is the issue any average electrician can fix it...bad IX don't think so,I don't think webcams are prone to failures,I mean those devices don't work 24/7.

I can open the webcam and picture inside,if that would help?

I'm not into electronics,I see there a lot of capacitors,power circuit with 2 coils ans 2 mosfets..

s judging by the PCB what could likely to fail?

[frozensun]

7 minutes ago, Moonzy said:

im thinking internal ribbon cable/wire

if it's a ribbon cable, it's pretty hard to fix though

dude where do you see ribbon cable?

[frozensun]

This dude got lucky,such an issue even I could try to fix it...

[Hackentosher]

2 hours ago, frozensun said:

My friends if the cable is the issue any average electrician can fix it...bad IX don't think so,I don't think webcams are prone to failures,I mean those devices don't work 24/7.

As @WereCatf said, it's probably not a USB cable issue because the device connects to your computer and initializes, but doesn't return any video correct? If that is the case, then the USB cable is fine. If it was damaged, you wouldn't have gotten that far. 

2 hours ago, frozensun said:

I can open the webcam and picture inside,if that would help?

Maybe, but look at the picture of that board. Imagine U7 is broken on it, for example. Assuming there's no obvious burn marks or corrosion, do you have the know-how and time to diagnose the true issue? If you do, I have a feeling it is well worth your time to not deal with this and buy a new camera. If not, I don't know what anyone on the internet can tell you beyond what you already know: shit's fucked.

2 hours ago, frozensun said:

I'm not into electronics,I see there a lot of capacitors,power circuit with 2 coils ans 2 mosfets..

Yeah this is a complicated board. I see impedance matched differential pairs, and I'm sure there's a mess of microcontrollers and other circuitry on the other side that we can't see from the picture posted above. 

2 hours ago, frozensun said:

s judging by the PCB what could likely to fail?

That is impossible to say without the device in one's hands and without the proper tools. You have an interesting, half failed case where the camera still "works" it's just not working 100%. The problem could be with any one of those components on the board. I wouldn't say there's any one component that is most likely to fail besides the cable (which has been ruled out), and we don't know if any of the components are closer to their rated maximum loads in this design (doubtful, but a possibility). If you want me to guess, I would start buy checking all of the power lines to and from the sensor, but that's assuming they're accessible on this board which does not appear to be the case. I'm sorry if this came off calloused, but there's no list of common failure modes for devices like this. I'm not discouraging you from opening it up and having a go at fixing it, but I think it's important to manage your expectations and realistically analyze your skills and knowledge before tackling a complicated device such as this. 

[Unimportant]

I can't imagine 4 SOT23-5 voltage regulators doing much talking over USB, so the party pieces of this camera are on the unseen backside of the PCB.

[WereCatf]

1 hour ago, Unimportant said:

I can't imagine 4 SOT23-5 voltage regulators doing much talking over USB, so the party pieces of this camera are on the unseen backside of the PCB.

Unlikely to matter, though. I'd be very much surprised if the issue was something that was actually visible with a naked eye; it's far more probable that one would need to get a multimeter out to find the issue, and OP doesn't have the skills for that, so...

[Unimportant]

53 minutes ago, WereCatf said:

Unlikely to matter, though. I'd be very much surprised if the issue was something that was actually visible with a naked eye; it's far more probable that one would need to get a multimeter out to find the issue, and OP doesn't have the skills for that, so...

Just pointing out the futility of people standing at the back of the car pointing and discussing why it won't run while the engine is in the front.

[frozensun]

Come on guys,webcam is device which is used like maybe 30 min to 2 h max per day....those devices are not really pron to fail,and this is not 20 year old cam,it's newer model...so must be smth particular that killed the webcam...

I could take it to local electrician but hmm I don't think even with his skills he can repair ir because I suppose replacement parts are hard to find....

[For Science!]

2 hours ago, frozensun said:

Come on guys,webcam is device which is used like maybe 30 min to 2 h max per day....those devices are not really pron to fail,and this is not 20 year old cam,it's newer model...so must be smth particular that killed the webcam...

I could take it to local electrician but hmm I don't think even with his skills he can repair ir because I suppose replacement parts are hard to find....

Well, it clearly did die, and both you and the previous owner were aware of this. The cause could be anything ranging from heat damage to water damage to static electricity damage.

 

Any number of components could have been damaged in the above mentioned possibilities and so it is impossible to gauge anything without at least very detailed pictures of a teardown of your parituclar webcam. Even with the teardown in the absence of obvious damage (salt crystals, water marks, burnt components) nothing can be done without some serious probing which you mentioned you are not skilled enough to do.

 

And even after all of that you should question whether the time and potential money is worth spending on this sub 100 euro webcam.

 

I think the situation here is clear, if you wanted to get a working webcam, you should have bought a working webcam. If you wanted to just take a risky bargain, you took the wrong risk. If you wanted a DIY repair project, you should actually put some effort into it instead of being so reliant on input from here without even having the present your own teardown.