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AP broken by owerpowering with 48V?

Dear all

 

By mistake we plugged in an AP AC LR bullet into an 48V PoE source instead of 24V.

 

Now the bullet shows no light or response at all if correctly powered with 24V.

The white light at the power supply flashes (is usually on constantly).

 

If we press the reset button a blue light flashes in the AP as long as we hold down the button.

 

Is there any way to recover it or is the hardware broken? (We heard about owerpower protection)

 

Thanks for any hint.

 

Sincerley... Mark.

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Re: AP broken by owerpowering with 48V?

It'd immensely help if you actually told us exactly which device model you plugged exactly into which PoE source and how was that PoE whatever configured.  AP AC LR and Bullet are totally different products.

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Re: AP broken by owerpowering with 48V?

Unfortunately in my experience of doing this it bricked the unit.

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Re: AP broken by owerpowering with 48V?

[ Edited ]

The overpower protection has shorted out. The flashing POE supply indicates the short across power and ground.

The AP AC LR is 'broken' hardware. You would need to open the case to remove/replace the over-voltage protection diode.

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Re: AP broken by owerpowering with 48V?

I've had a customer do the same - plugging a number of UAP AC-Lite's into reg. 48v POE port...

 

This bricked the device but I 'fixed' it by removing D6 as can be seen in attached photo.

 

IMG_0121.JPG

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Re: AP broken by owerpowering with 48V?

Yes, that's the voltage suppression diode device. By removing a failed TVS, you remove the short across power and ground, allowing the unit to work.

It won't have the TVS protection anymore, of course, and another voltage spike will probably kill the device.

Also, it needs to be said, opening up the case voids any warranty you might have.
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Re: AP broken by owerpowering with 48V?

[ Edited ]

Indeed. Warranty is void after this 'repair' (but fixing it was prob not covered by warranty anyway) and the device will be positively smoked (or worse) if you overpower it again.

 

 

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Re: AP broken by owerpowering with 48V?

[ Edited ]

dday wrote: I've had a customer do the same - plugging a number of UAP AC-Lite's into reg. 48v POE port...

 

This bricked the device but I 'fixed' it by removing D6 as can be seen in attached photo. 

 


Thanks for the super detailed photo! Nice that it has the exact same two antenna jacks like the three in the UAP-AC-PRO.

 

-Jamie M.

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Re: AP broken by owerpowering with 48V?

I’ve seen this happen several times but never realized it could be easily fixed. I simply switched to the UAP-AC-Pro and swore off passive POE in office environments.

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Re: AP broken by owerpowering with 48V?

Dear all

 

Thanks for the many answers already.

 

I apologize for not having provided detailed data.

 

The AP model is: UAP AC LR. 24V 0.5A GigE PoE, IC: 6545A-UAPACLR.

The Power supply for 24V is: GP A240-050G, PN 24-12W-G.

 

Picture of the top side of the mainboard is attached.

 

Am I correctly assuming that I need to remove either D24 or D23 or both?

 

Thanks again for your help. This is a money-saver!

 

Sincerely.... Marc.

 

 

 

 

 

x.jpg
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Re: AP broken by owerpowering with 48V?

Need a closeup

TVS is usually labeled 'GEZ'
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Re: AP broken by owerpowering with 48V?

Hello

 

D23 is labeled with LZ 6A1BF

D24 is labeled with 550 B260A

 

Thanks again for your help.

 

Mark.

 

 

 

20161115_220812.jpg
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Re: AP broken by owerpowering with 48V?

I would say it's D23, but I'm by no means an expert nor do I have an UAP-LR myself...

 

You can easily measure it with a multi-meter. If the diode shorts to ground (actually in a failed state it will conduct in both directions) it's broken and prob the problem.

 

What's on the other side of the board?

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Re: AP broken by owerpowering with 48V?

Aren't all future access points supposed to be only 48v or 802.3 af/at compatible? (I might have the standard wrong, forgive me)

I've always been curious why Ubiquiti sells POE devices that don't adhere to the 802.3 af/at standard.
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Re: AP broken by owerpowering with 48V?

Passive POE is commonly used by WISPs. Ubiquiti started in the WISP market.

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Re: AP broken by owerpowering with 48V?

Ah, I had no idea about Wisps. Thanks tekelenberg
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Re: AP broken by owerpowering with 48V?

Dear all

 

I can hereby confirm that it is D23.

However it is nearly impossible to unsolder it as there's nearly no tin-solder.

I used a small carpet knife to carefully cut through the pin of D23 on one end in a way I could solder it again if I were wrong.

 

It worked.

 

Thanks to everybody for helping. Mark.

 

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Re: AP broken by owerpowering with 48V?

[ Edited ]

In cases where there's no solder to un-solder (meaning it's hard to heat the existing joint) I usually add a bit of my own solder.

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Re: AP broken by owerpowering with 48V?

@infoatvorbrodt not a lot of pics of the UAP-AC-LR innards out there...before you put it back together, any chance you can take a picture of the other side of the board (non-antenna side)?

 

Thanks!

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Re: AP broken by owerpowering with 48V?

@dengkai

 

Have a look at the internal photos which was submitted to the FCC.  Would this surfice?

 

Internal Photos

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