broken dahua with wrong 12V...

F

frank10

Getting the hang of it
Sep 13, 2015
178
11
My friend has 2 cat6 wires on a pole and wrongly connected 2 wires on 12V thinking it was the other cable, instead they went on the ethernet connection of the cam...
Long story short, the Dahua 4421r-as ipcam doesn't power up anymore!
Is there something could I try? I opened it but I don't see any exploded/damaged parts...
Any hints?
 

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  • Dahua4421R-as_Inside.jpg
    Dahua4421R-as_Inside.jpg
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No, it doesn't lit.


Looking at this pic:

Spoe%20Cable%20Again_1.jpg


he put +12 on wire blu on pin 6 and GND on blue/white on pin 3.

Looking here:

Pin-Out-Table.jpg


+ should go on pins 1-2 and -(gnd) on pins 3 and 5.

It seems it's fine apart the pin 6 +12V... but it seems unused on POE.
But I thought it will be used instead, also looking at previous pic...
 
I'm guessing the camera worked fine before your 12v error? If so and you've tried a 12v power adaptor and you still don't get any IR lights it doesn't sound good.
Looking at a close up of your circuit board, the highlighted chip looks slightly blown. But hard to tell from the magnified picture.
Next course of action you could try to see if it's been bricked by the power surge and attempt a unbricking process via telnet / putty
upload_2016-12-1_13-14-49.png
 
But to try with telnet, at least the camera should be on, instead I see with a power meter 0W.
 
You are correct but It was just a shot in the dark that the camera was bricked and failing to boot. If as you say there is nothing at all then I'm at a loss as to what else you could try apart from component level repair!
 
But is there some aliexpress seller that can sell the motherboard only? Or should I try to ask some normal seller if he can obtain it?
Anyone did this?
 
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f6c.jpg


spare parts are generally not available.
 
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Well now you have a spare in case you break another camera in another way?
You could check eBay or AliExpress for that IC and replace it. You'll need a hot air gun, soldering iron with small tip and lots of solder flux.
Obviously other stuff could be damaged as well. Or the IC might need to be programmed..

Can you identify the burnt IC? Give us the text on top of it, maybe you can power the camera with an external power supply to check if it still works.
 
Looking at the picture I think I see a blown SMD capacitor on the far right under the GROUPTEK IC and above the e-cap.
 
cor35vet said:
Looking at the picture I think I see a blown SMD capacitor on the far right under the GROUPTEK IC and above the e-cap.
Click to expand...
I don't think the photo's good enough to make any meaningful visual determinations. You need a real camera in macro mode and have to be really careful with your exposure/lighting/flash to avoid getting everything washed out from the flash.

Whatever chip provides the ethernet PHY and even the magentics in the jack could easily be blown if not all sorts of other things.
 
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I made some better photos front/retro with a lighted lens:
Imgur a/bxY2h


BTW: the forum don't let me put the correct link of this imgur album...
So:
www. imgur .com/ a/bxY2h

remove the spaces...

EDIT:
corrected link
 
Last edited:
I made a fast collage of previous pics to read better the components:

Front:

DahuaFront_collage.jpg

Rear:
DahuaRear_collage.jpg

What do you think?
could I solve this issue replacing the Ethernet chip on front
1 Piece New MNC H1601CG SOP16 | eBay

If wrong Voltage was feed in Ethernet wires, it should be the first to have blowed out.
What else?
 
cor35vet said:
Looking at the picture I think I see a blown SMD capacitor on the far right under the GROUPTEK IC and above the e-cap.
Click to expand...
Yes, you're right, it seems it completely lacks (exploded?) a capacitor!

EDIT:
No, I opened another Dahua I have and I saw the same: it's designed to miss.
 
It's just too hard for most people to diagnose things like this, even if you've got the tools, skills, and knowledge required sourcing the parts can be a nightmare. Even if I had a full schematic and English data sheets for every chip on there, and all the needed parts on hand, it could easily take a couple hours to fix.

As much as I like to fix things, I just don't see it being worth the time.
 
Arggh, I discovered another thing!
I found out that I gave 12V with the external power with a connector similar to the right one, but slightly different more "large" inside, so it didn't make the contact inside: infact the Watt meter gave 0W.
With another connector instead, it says 2W! So, at least the camera powers up... The other Dahua, the working one, says 3W, something more, maybe the stream.

So, it powers, but BI doesn't see the ip of the camera (I tried also to reset it with the inside button).
Probably it is that Ethernet chip gone. I mean, IF it is only that chip, it could be worth to replace it for 2€.

Is there some other test could I try apart BI on the Ethernet?
 
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