Dahua PoE failure rate

P

poptix

n3wb
Jan 19, 2016
19
14
I'm seeing a relatively high failure rate (7 out of 32 cameras, so far) at a specific site installed in late 2019. Most (but not all!) of the cameras are on LR1002-1ET transmitters (Single-Port Long Reach Ethernet over Coax Extender) coupled with LR1002 (EoC Passive Converter).

In both configurations the dead component is the 802.3af -> 12v downconverter module inside the camera.

  • Indoor, climate controlled, no burn marks, no water nearby.
  • The dead cameras were powered by two separate Cisco switches on UPS, in different parts of the building.
  • I've seen the same problem at different sites, though not nearly so often.

Is this common? Are replacement modules available? So far I've just been dropping in the PoE -> 12v converters but they're a bit of an eye sore in some spots and I shouldn't have to do it in the first place.

PXL_20230927_223052012.jpg
 
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What camera model? I seem to recall a thread here of someone having a high rate of failure with one model (but I do not recall which one but thought it was one of the budget-friendly models).
 
I have installed hundreds of Dahua cameras, have had very few problems with the cameras that were in installed, I did have one cvi camera go mad after a weird power outage, I have never had a Dahua PoE IP camera fail to date. I do live in an area with lower temperatures
 
poptix said:
I'm seeing a relatively high failure rate (7 out of 32 cameras, so far) at a specific site installed in late 2019. Most (but not all!) of the cameras are on LR1002-1ET transmitters (Single-Port Long Reach Ethernet over Coax Extender) coupled with LR1002 (EoC Passive Converter).

In both configurations the dead component is the 802.3af -> 12v downconverter module inside the camera.

  • Indoor, climate controlled, no burn marks, no water nearby.
  • The dead cameras were powered by two separate Cisco switches on UPS, in different parts of the building.
  • I've seen the same problem at different sites, though not nearly so often.

Is this common? Are replacement modules available? So far I've just been dropping in the PoE -> 12v converters but they're a bit of an eye sore in some spots and I shouldn't have to do it in the first place.

View attachment 173403
Click to expand...

Anyway, no not normal from what we’ve seen here. I’ve lost two over the years but both were from moisture
 
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I'm thinking that it could be a bad batch of modules with a specific component o the board being marginal.

I also am not aware of such a high failure rate of Dahua POE cams.
You listed all the attributes for a long-life: indoors, no water, UPS, etc. but what stands out is 32 cameras of the same brand, all likely manufactured about the same time frame....hallmark signs of a "bad" batch of the POE boards.

It is strange though that "Most (but not all!) of the cameras are on LR1002-1ET transmitters coupled with LR1002".......makes me wonder a bit, too. :wtf:
 
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Also:
  • What is your geographic area?
  • Are these in a building with any medical X-ray, diathermy or MRI devices?
  • Are these in a building with automotive magnafluxing equipment?
  • Is there a large municipal or military airport nearby?
  • Is there a large radio transmission tower nearby?
 
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I would measure the capacitors for short.
 
They're HDW4831EM and HDW4631EM from Andy. The building doesn't have any weird equipment in it, don't seem to be lightning correlated either.

I'm leaning towards the bad batch theory, I'll have to spend some time probing them to see what exactly failed.
 
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I'm 90% that some capacitor is shorted. Check those brown capacitors. The black ones are resistors, and those two big black ones are inductors(those will show short).
 
tibimakai said:
I'm 90% that some capacitor is shorted. Check those brown capacitors. The black ones are resistors, and those two big black ones are inductors(those will show short).
Click to expand...
Caps that small ("capacitance-wise") shorted? I'd be VERY surprised....open maybe.
But high amplitude, short duration ESD and back-EMF from collapsing coils (or at the end of a very long length of cable) can do strange things.
 
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Yes, shorted smd caps. I have just fixed a JVC Dila-X500 projector, that had a shorted smd cap in the ballast daugherboard.
I have fixed quite a few other devices in the past, even security cameras, that had shorted caps.
 
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tibimakai said:
Yes, shorted smd caps. I have just fixed a JVC Dila-X500 projector, that had a shorted smd cap in the ballast daugherboard.
I have fixed quite a few other devices in the past, even security cameras, that had shorted caps.
Click to expand...
I guess it's a thing with SMD'd. Back in the 70's thru early 90's the discrete ceramic caps (very low uF) lasted forever and the axial lead electrolytics as filters and decouplers (10uF to 1,000uF and up) lasted quite a while but usually failed open. Heat and too much ripple current due to poor design were their biggest enemies.....times have changed. :cool:
 
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For sure they have changed. In 2008-2010 Samsung TVs were going bad because of capacitors, were bulging.
 
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tibimakai said:
For sure they have changed. In 2008-2010 Samsung TVs were going bad because of capacitors, were bulging.
Click to expand...
That's about the time I started bulging......:winktongue:
 
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