DAHUA PoE camera does not power with Poe switch but powers with 12v adapter

7tech

n3wb
Oct 24, 2022
3
3
Cameroon
M’y DAHUA up cameras doesn’t power on when connected to PoE switch but it powers on when I connect a 12v adapter. What could be the problem with the PoE line and how to solve it?
 

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Do you have much lightning in your vicinity? If so, the chip inside the camera or the POE port on your POE switch may have been damaged by ESD due to a nearby strike.
Have you tried another port on the switch?
Have you tried another Ethernet cable/ inspected the camera's pigtail connection for corrosion?
I see you are able to inspect the inside of the camera...any visible damage such as black areas or damaged traces? Any burnt smell?

P.S. - Welcome to IPCT ! :wave:
 
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What poe switch are you using? Are there other POE PD? What PSU are you using for the switch?
 
Do you have much lightning in your vicinity? If so, the chip inside the camera or the POE port on your POE switch may have been damaged by ESD due to a nearby strike.
Have you tried another port on the switch?
Have you tried another Ethernet cable/ inspected the camera's pigtail connection for corrosion?
I see you are able to inspect the inside of the camera...any visible damage such as black areas or damaged traces? Any burnt smell?

P.S. - Welcome to IPCT ! :wave:
Yes I’ve changed ports on the switch and change cables too. Also there’s No visible damage, no pigtail corrosion and no burnt smell as well. My other DAHUA PoE cameras are working just fine on the same Poe switch.
 

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Yes I’ve changed ports on the switch and change cables too. Also there’s No visible damage, no pigtail corrosion and no burnt smell as well. My other DAHUA PoE cameras are working just fine on the same Poe switch.
FWIW, I've a couple of POE cameras and one 12vdc wall wart camera damaged by lightning's ESD in recent years and none of them had any visible or detectable damage.
One was in a boot-up loop, one dead as a door nail and one would not communicate....all different and all useless.
 
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Thank you guys for your replies. Maybe I just have to replace this particular camera or keep using it with the 12v adapter then because it works just fine when powered with the 12v adapter. It just won’t work with the Poe switch like the other cameras I have.
 
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A very nearby Lightning strike/ESD apparently fried my Zyxel POE switch a few days ago. IP ports OK, just no POE output. Just now replaced it with a Netgear GS308PP and found 2 Dahua's came back online fine, and 2 did not. One other Ethernet-attached component (non-POE) also would no longer connect, but nothing else in the house was affected. Weird how selective this hit was.

Both of the disabled Dahua's would power up just fine and worked perfectly with a 12V PS, but that's not going to fly on the far corners of my house. I'm going to try an inexpensive POE 12V/1A splitter to solve this problem and keep the camera on POE power. @7tech - you might want to try this vs a 12V adapter or having to replace the camera. My cabling is coming through the roof soffit, so I'll just make the hole a bit bigger to weather protect this splitter. I'll update this post if it works as expected.

Although all of my network equipment is attached to a high quality UPS, it failed to provide the necessary ESD protection. I'm adding an Eaton whole house surge protector today as well. Shoulda done that already.
 
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I had this same issue with a Loryta IPC-HFW5241E-Z12E. It took a couple of back-and- forths to Andy, but ultimately it was decided the POE circuit was faulty.

I would do what you have already deduced. Replace or use with 12v power, if possible.
 
A very nearby Lightning strike/ESD apparently fried my Zyxel POE switch a few days ago. IP ports OK, just no POE output. Just now replaced it with a Netgear GS308PP and found 2 Dahua's came back online fine, and 2 did not. One other Ethernet-attached component (non-POE) also would no longer connect, but nothing else in the house was affected. Weird how selective this hit was.

Both of the disabled Dahua's would power up just fine and worked perfectly with a 12V PS, but that's not going to fly on the far corners of my house. I'm going to try an inexpensive POE 12V/1A splitter to solve this problem and keep the camera on POE power. @7tech - you might want to try this vs a 12V adapter or having to replace the camera. My cabling is coming through the roof soffit, so I'll just make the hole a bit bigger to weather protect this splitter. I'll update this post if it works as expected.

Although all of my network equipment is attached to a high quality UPS, it failed to provide the necessary ESD protection. I'm adding an Eaton whole house surge protector today as well. Shoulda done that already.
My house was directly struck by lightning 2 years ago. It is amazing what it did and did not damage. My NVR, DVR, cameras, etc were all fine; it just fried the ethernet ports on the NVR and DVR. My Living Room TV? Fine, but it fried the ARC HDMI port. My FireStick? It fried the ARC control portion. I ended up replacing all of the ethernet in the house because items would be replaced and then the connection wasn't there.
 
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Thanks Ri22o for sharing. "Replace or use with 12v power "???

While often damage like this is a good excuse for upgrading to newer tech, my Dahua's were fairly new. Close to $400 to replace both, compared to $15 for 2 POE splitters with no need to run additional cable... just weatherproofing them. These new splitters are said to have overvoltage protection as well.
 
Also, try a different the CAT5 cable to connect the camera to the POE switch. That's because POE uses additional wires in the cable, which might be damaged.
This is not correct. Unless there are exceptions I never heard about, all POE switches use mode A, which sends both power and data over the orange and green cable pairs, with the blue and brown pairs unused. Injectors generally use mode B, sending the power over the pairs that are not used with mode A.
 
If you are looking to repair it, here is what the power circuit might look like. Simplified, there will be more devices hanging off it for circuit protection, but shows the basic flow. Finding replacement chips might be tough. Your best hope is finding a bad solder joint along the circuit between the cable input and the 12V DC regulator.

The transformer, T1, you can check the output pins to find voltage in the range of 37-54V.
That goes into a rectifier - PoE compliant devices need to support both power on the data pairs and the spare pairs, so you should see 2 rectifiers, MB8S on the bottom under the transformer. You should see 54V on one of the MBS8 at the +/- pins.

The 54V should then connect to a DC/DC to make 12V. Power down and try to follow/beep where the + on the MB8S connects, likely near T3.

That 12V should join up with the DC input, likely with a diode OR.

If this got hit by lightning, I'd expect the TVS to be blown and the PHY to also be blown (no network connection).

Good luck.
Capture.PNG
 
Thanks very much for this detailed schematic and analysis!

I am happy to report that the $5 POE splitter worked out great to resurrect both of my "blown" cameras. Well, except the 50' Ethernet cable to one of the cameras isn't providing power for some unknown reason. (Camera/splitter works perfectly connected to POE switch with a different cable).

As soon as it stops raining here, I'll attach an Ethernet cable tester to try to determine what's wrong with the end connections or cable. Visually, I see no problem with the RJ45 connectors. Worst case, I'll have to run a new CAT6 cable through attic. Best case, just repunch new ends.

UPDATE: The tester shows that Ethernet cable data pair 3 & 6 have no continuity. So apparently an ESD hit fried not just the POE switch and POE camera circuit, but these 2 wires somewhere in the cable.
 
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I just noticed some odd tiny pits in the camera cover and body. I assume these were from the lightning/ESD strike. All 4 of my cameras are mounted on the roof fascia with direct contact to aluminum guttering as can be seen here. Only 1 camera has these burn pits.

I wonder if the lightning went into the ground somewhere up the downspouts through the guttering and then this camera and on into the POE switch? Consequently this fried the switch and one other camera POE circuit but not the other 2? There were other devices that died that weren't on this switch, so it's still possible the damage entered from the main power lines and found its way to ground via the camera/gutters.

In any case, I'll squeeze some thin insulating plastic between the camera/gutter to at least avoid direct contact. Would have to cut trim otherwise to drop them lower.

Camera ESD.png
 
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So the cameras survived? The cool thing about ethernet is it's all balanced cabling with isolation transformers on each end. But parts are typically rated to 2kv isolation. Lightning will exceed that easily. Good idea to isolate the cameras from grounding the strike, let it find another path.
 
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Yes! Both cameras are back in operation using the POE splitter. I had to run a new 50' Ethernet cable to one of the cameras as a data pair was broken somewhere along the line. It is amazing that the camera (IPC-T5442T-ZE) survived the metal-pitting voltage. The POE switch sure didn't survive.
 
I am having the same problem with SD59225 ptz camera. Was working on PoE+ until recently. Can also power up using 25V AC external power. Is there an injector available to provide 25 VAC @ 2A available?