DLink access point emitting high frequency sound?

[Alaza]

Hello,

I have a D-Link 3200AP which just died on me. And in that regard it started emitting a high frequency tone. Am I correct to assume that its usually inductors doing that?

In any case, I have uploaded a picture of the inductor I can see on the print. I have not been able to find a schematic for the circuit, but it seems to be easy to replace components, so should I just go for changing the inductor? I was thinking though, that for it to resonate at a different frequency than what it was designed for, it must be the circuit around it that's not working properly?

**broken link removed**

Thank you

 

[Brevor]

Inductors dont usually go bad, unless it has come loose and is vibrating. Try holding your finger on it to see if the noise stops. Also try this on the electrolytic capacitors around the coil. If you find something that is vibrating use some silicone RTV to hold it down to the PC bd.

 

[Alaza]

Thank you for the quick reply.

There is no vibration from any of the caps, nor the inductor. Do you have any other ideas?

I discovered though, that there might be a warranty for it still, so I might try that too.

 

[Mickster]

If you have disturbed any anti-tamper measures on this unit, that warranty will now be void...

 

[Alaza]

I don't see any seal or the like that have been broken, so I'm hoping for the best.

 

[KeepItSimpleStupid]

Exercise the warranty first.

How about a pic that's near the power supply input? Inspect the board forbad solder joints, bottom and top.

 

[Alaza]

I have left it at work waiting for RMA reply from D-Link. I have checked for bad solderings and other defects, but there were nothing to be seen, it was actually in surprisingly good physical condition. I will be back with more information and pictures if they don't accept it for replacement.

Thank you guys.

 

[Nigel Goodwin]

Whistling is normally one of the inductors, a drop or two of glue often cures them.

 

[Alaza]

Is it because the windings change characteristics so the resonancy frequency moves over time or?

 

[Nigel Goodwin]

Is it because the windings change characteristics so the resonancy frequency moves over time or?

It's because the windings work loose and then vibrate.

 

[Alaza]

Alright, nice to know. But furthermore it doesn't work properly, so I will have a closer look at it if the RMA doesn't go through.

 

[Nigel Goodwin]

Not working as well is a very different matter - usually showing it's being overloaded (often a S/C diode or capacitor).

 

[Diver300]

I have also had inductors similar to that go short circuit. That leads to saturation and squeaking. In a buck regulator, the efficiency is lost, and that can lead to the device not working.