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UAP-AC-IW no POE for specific cable only

So one of my UAP-AC-IW's was working flawlessly for the past several months until about a few days ago when I noticed that it was in a disconnected state in the cloud controller interface. I checked the AP and true enough it didn't have lights in it. So my first test was to open it up and do a cable test from end to end (around 63 meters) and surprisingly everything was working just fine. But still no PoE. I then brought the AP with me and directly connected it to the same switch on the exact same port and was again surprised that it worked!I then put everything back up and now I tested connecting the same 63m cable from the switch to a laptop and it worked! But any other PoE device isn't working.

 

So the only thing that could cause this is the current cable that it was using but I really can't get my head around this question:

 

Non-PoE Gigabit connection is working so that means all 4 pairs are working properly. But why won't PoE turn on if all 4 pairs are good anyway and again "only for this specifica cable"?

 

For reference, I have the exact same scenario as this guy here. He didn't really know what caused the issue and just went with replacing the cable to solve the issue but that isn't my first choice. I want to know first what caused the issue. Any recommendations on where to start? I did a simple cable test within the properties section of my laptop's Intel network adapater and everything passed with flying colors!

 

I really can't get my head wrapped around this issue. Please help. Thanks.

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Re: UAP-AC-IW no POE for specific cable only

Do you have a PoE Tester? You'll want to check the voltage you're receiving near end and far end. If a cable is out of spec or going bad, you'll experience a voltage loss. 

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Re: UAP-AC-IW no POE for specific cable only

[ Edited ]

"I want to know first what caused the issue." First of all, bravo to you! Too many people just want to throw parts at problems until they resolve. You may end up replacing after all, but at least you will know WHY, which makes for a better future tech.

Is the cable good quality, e.g., is it solid copper and not copper-clad aluminum? Cable runs between end points should be solid cable and not stranded.

 

What gauge is your cable? A thin cable will pass data much better than it can transmit PoE, so a laptop can work fine while PoE devices fail. Even CAT5E 24AWG can do PoE well.

 

Is the cable terminated by the manufacturer, or by you? If you did it and you terminated the cable to RJ45 plugs, I recommend re-terminating, but do it to keystone jacks or patch panel and keystone, depending upon how you are set up. Then use a factory made patch cable from the jack to the AP and from the switch to patch panel or that end's keystone jack.

 

What kind of tester did you use? If it's a cheap tester that only tests one wire at a time, it can show all 8 wires as good, even though the pinouts are incorrect or the cable has split pairs. If you don't want to buy a tester that can test PoE load, then if you know someone in the cabling industry, pay them to test the cabling and make sure they have a tester that can test the PoE load, and not just PoE voltage. I am a network guy, not a cabler, and I have two good Fluke testers (CableIQ and LRAT-2000), but only the latter can test load. Both have saved my butt when other testers showed cables as good.

 

EDIT: I may buy one of these https://www.amazon.com/WS-PoE-Tester-Inline-Voltage-Current-Detector/dp/B07PFRMH5N just to satisfy my curiosity and compare it to the LRAT-2000's results. I also have LinkSprinter 300 that tests PoE voltage, but cannot test it under load.

Gregg

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Re: UAP-AC-IW no POE for specific cable only


@greggmh123 wrote:

"I want to know first what caused the issue." First of all, bravo to you! Too many people just want to throw parts at problems until they resolve. You may end up replacing after all, but at least you will know WHY, which makes for a better future tech.

Is the cable good quality, e.g., is it solid copper and not copper-clad aluminum? Cable runs between end points should be solid cable and not stranded.

 

What gauge is your cable? A thin cable will pass data much better than it can transmit PoE, so a laptop can work fine while PoE devices fail. Even CAT5E 24AWG can do PoE well.

 

Is the cable terminated by the manufacturer, or by you? If you did it and you terminated the cable to RJ45 plugs, I recommend re-terminating, but do it to keystone jacks or patch panel and keystone, depending upon how you are set up. Then use a factory made patch cable from the jack to the AP and from the switch to patch panel or that end's keystone jack.

 

What kind of tester did you use? If it's a cheap tester that only tests one wire at a time, it can show all 8 wires as good, even though the pinouts are incorrect or the cable has split pairs. If you don't want to buy a tester that can test PoE load, then if you know someone in the cabling industry, pay them to test the cabling and make sure they have a tester that can test the PoE load, and not just PoE voltage. I am a network guy, not a cabler, and I have two good Fluke testers (CableIQ and LRAT-2000), but only the latter can test load. Both have saved my butt when other testers showed cables as good.

 

EDIT: I may buy one of these https://www.amazon.com/WS-PoE-Tester-Inline-Voltage-Current-Detector/dp/B07PFRMH5N just to satisfy my curiosity and compare it to the LRAT-2000's results. I also have LinkSprinter 300 that tests PoE voltage, but cannot test it under load.

Gregg


Yeah, it's always better to know the root cause of a problem anyway.

 

So the setup for that specific cable is like this:

 

UniFi Swtich -> factory-made patch cable (Monoprice) -> patch panel -> rj45-terminated (by me) Belden CAT6 cable -> cat6 female-to-female coupler -> rj45-terminated (by me) D-Link CAT6 cable -> UAP-AC-IW

 

Belden cable - CAT6, UTP, 24AWG, solid

D-Link cable - CAT6, UTP, 23AWG, solid

 

I tried plugging the AP to the other side of the coupler and everything is working so we're sure that there is no problem from the UniFi switch up to the coupler. So the only thing to blame as the culprit would be the 63m D-Link cable run. I'm not a noob in terminating CAT6 cables but the problem is that I don't have enough cable anymore to do a re-termination (which is why I was already using a coupler so that it'll reach the patch panel).

 

And yes, I'm using a cheap simple tester that has been working for me until now. I'd also say that replacing the cable would be more economical than buying a better tester as I'm doing this in our house only. I don't do this as a profession but I know enough.

 

So I guess the only thing left here to do is to replace the cable if I don't want to buy a tester. The only way to know the cause is to have a tester Man Sad

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Re: UAP-AC-IW no POE for specific cable only


@kevindd992002 wrote:

@greggmh123 wrote:

snip


Gregg


Yeah, it's always better to know the root cause of a problem anyway.

 

So the setup for that specific cable is like this:

 

UniFi Swtich -> factory-made patch cable (Monoprice) -> patch panel -> rj45-terminated (by me) Belden CAT6 cable -> cat6 female-to-female coupler -> rj45-terminated (by me) D-Link CAT6 cable -> UAP-AC-IW

 

Belden cable - CAT6, UTP, 24AWG, solid

D-Link cable - CAT6, UTP, 23AWG, solid

 

I tried plugging the AP to the other side of the coupler and everything is working so we're sure that there is no problem from the UniFi switch up to the coupler. So the only thing to blame as the culprit would be the 63m D-Link cable run. I'm not a noob in terminating CAT6 cables but the problem is that I don't have enough cable anymore to do a re-termination (which is why I was already using a coupler so that it'll reach the patch panel).

 

And yes, I'm using a cheap simple tester that has been working for me until now. I'd also say that replacing the cable would be more economical than buying a better tester as I'm doing this in our house only. I don't do this as a profession but I know enough.

 

So I guess the only thing left here to do is to replace the cable if I don't want to buy a tester. The only way to know the cause is to have a tester Man Sad


"I'm using a cheap simple tester that has been working for me until now."

I have met a few people who thought the same thing, but never realized their testers were not checking for split pairs. My tester showed they had split pairs.

 

 

 

"...I don't have enough cable anymore to do a re-termination"

Don't you have two inches to put new RJ45 terminals on it? Or even better, two inches to punch into keystone jacks, then use short patch cables from those ends to the coupler and the AP? At least cut off the RJ45 at the AP end of the cable, punch it into a keystone jack, then use a short patch cable from the keystone to the UAP-AC-IW. Do both ends if possible. I find punching into keystone jacks is FAR more reliable than terminating a solid cable run with RJ45 terminals.

Gregg

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Re: UAP-AC-IW no POE for specific cable only


@greggmh123 wrote:

@kevindd992002 wrote:

@greggmh123 wrote:

snip


Gregg


Yeah, it's always better to know the root cause of a problem anyway.

 

So the setup for that specific cable is like this:

 

UniFi Swtich -> factory-made patch cable (Monoprice) -> patch panel -> rj45-terminated (by me) Belden CAT6 cable -> cat6 female-to-female coupler -> rj45-terminated (by me) D-Link CAT6 cable -> UAP-AC-IW

 

Belden cable - CAT6, UTP, 24AWG, solid

D-Link cable - CAT6, UTP, 23AWG, solid

 

I tried plugging the AP to the other side of the coupler and everything is working so we're sure that there is no problem from the UniFi switch up to the coupler. So the only thing to blame as the culprit would be the 63m D-Link cable run. I'm not a noob in terminating CAT6 cables but the problem is that I don't have enough cable anymore to do a re-termination (which is why I was already using a coupler so that it'll reach the patch panel).

 

And yes, I'm using a cheap simple tester that has been working for me until now. I'd also say that replacing the cable would be more economical than buying a better tester as I'm doing this in our house only. I don't do this as a profession but I know enough.

 

So I guess the only thing left here to do is to replace the cable if I don't want to buy a tester. The only way to know the cause is to have a tester Man Sad


"I'm using a cheap simple tester that has been working for me until now."

I have met a few people who thought the same thing, but never realized their testers were not checking for split pairs. My tester showed they had split pairs.

 

 

 

"...I don't have enough cable anymore to do a re-termination"

Don't you have two inches to put new RJ45 terminals on it? Or even better, two inches to punch into keystone jacks, then use short patch cables from those ends to the coupler and the AP? At least cut off the RJ45 at the AP end of the cable, punch it into a keystone jack, then use a short patch cable from the keystone to the UAP-AC-IW. Do both ends if possible. I find punching into keystone jacks is FAR more reliable than terminating a solid cable run with RJ45 terminals.

Gregg


I see. If you have split pairs though, won't the signal sent by the transmietter through one pair (say 1 and 2) of the cheap tester be received on another pair (say 3 and 4) and would be obvious to me? That's how I looked at it. If I want to buy a tool to test this, would the one you link be the cheapest but reliable tool that I can get? Or can you recommend a good Fluke tester that I can probably get off of eBay?

 

I do have a couple of inches more on the AP end of the cable but not on the coupler end. I agree that using keystone jacks is far more stable than RJ45 terminals but you won't be able to install the AC-IW if you use keystone jacks because the wire is directly connected behind it. But yeah, the least I can do now is to try and do another re-termination.

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Re: UAP-AC-IW no POE for specific cable only

I just bought a Klein Tools Scout Pro 2 network cable tester and it can detect split pairs. I have that tool is enough to determine what's causing the problem before I try re-crimping the connectors.

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Re: UAP-AC-IW no POE for specific cable only


@kevindd992002 wrote:



I see. If you have split pairs though, won't the signal sent by the transmietter through one pair (say 1 and 2) of the cheap tester be received on another pair (say 3 and 4) and would be obvious to me? That's how I looked at it. If I want to buy a tool to test this, would the one you link be the cheapest but reliable tool that I can get? Or can you recommend a good Fluke tester that I can probably get off of eBay?

 

I do have a couple of inches more on the AP end of the cable but not on the coupler end. I agree that using keystone jacks is far more stable than RJ45 terminals but you won't be able to install the AC-IW if you use keystone jacks because the wire is directly connected behind it. But yeah, the least I can do now is to try and do another re-termination.


"won't the signal sent by the transmietter through one pair"

Yes, if it tests PAIRS of wires. I have seen some testers that test one wire at a time, and if all eightwires are connected end to end, it declares the cable good. That kind cannot detect split pairs.

I am having trouble picturing how you "won't be able to install the AC-IW if you use keystone jacks because the wire is directly connected behind it" is an issue. Can't you terminate the cable to a keystone, plug in a short patch cable to the keystone, push the keystone into dead space in the wall, then plug the end into the IW? That is what I did when I replaced a wall jack with a UAP-AC-IW...I just popped the keystone out of the wall plate, connected a 1' patch cable, and stuffed the keystone above the AP in the wall.

Gregg

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Re: UAP-AC-IW no POE for specific cable only


@greggmh123 wrote:

@kevindd992002 wrote:



I see. If you have split pairs though, won't the signal sent by the transmietter through one pair (say 1 and 2) of the cheap tester be received on another pair (say 3 and 4) and would be obvious to me? That's how I looked at it. If I want to buy a tool to test this, would the one you link be the cheapest but reliable tool that I can get? Or can you recommend a good Fluke tester that I can probably get off of eBay?

 

I do have a couple of inches more on the AP end of the cable but not on the coupler end. I agree that using keystone jacks is far more stable than RJ45 terminals but you won't be able to install the AC-IW if you use keystone jacks because the wire is directly connected behind it. But yeah, the least I can do now is to try and do another re-termination.


"won't the signal sent by the transmietter through one pair"

Yes, if it tests PAIRS of wires. I have seen some testers that test one wire at a time, and if all eightwires are connected end to end, it declares the cable good. That kind cannot detect split pairs.

I am having trouble picturing how you "won't be able to install the AC-IW if you use keystone jacks because the wire is directly connected behind it" is an issue. Can't you terminate the cable to a keystone, plug in a short patch cable to the keystone, push the keystone into dead space in the wall, then plug the end into the IW? That is what I did when I replaced a wall jack with a UAP-AC-IW...I just popped the keystone out of the wall plate, connected a 1' patch cable, and stuffed the keystone above the AP in the wall.

Gregg


I see what you're saying and it can work actually but why would you want to do tht if I can just try and re-crimp with an RJ45 connector? That's because I don't have a 1' pre-made factory cable so I'll make my own anyway and would result to the same thing.

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Re: UAP-AC-IW no POE for specific cable only

You still could have a crimp good enough to pass data but not good enough to pass PoE. It's a good start, but a PoE tester may help.

 

I am also trying to fathom how you have enough cable to connect to a coupler, but not enough to cut off the terminal and use a keystone jack, then a short patch cable to the coupler. You must have two VERY tight cable runs. Cutting a terminal and using a jack would shorten the cable by less than an inch.

 

Gregg

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Re: UAP-AC-IW no POE for specific cable only

How much space do you have inside the wall, assuming that is where the IW is mounted? The patch cable can be whatever length you can stuff inside the wall with damaging it...two or three feet.

 

In this case, due to your PoE problems, I'd stop using hand-made RJ45 terminated cables.

 

Before you do anything else, have you put your crimper onto the current terminals and given them another good squeeze? Sometimes a weak crimp can be fixed that way.

Gregg

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Re: UAP-AC-IW no POE for specific cable only

I mean I can but then it would be very tight but I won't know for sure if I don't try. I won't be on-site until the 19th though so we'll have to put this on a hold.

 

Say there are no split pairs or any connectivity issues with the cable, what else could cause the PoE issue? What would the PoE testee tell you anyway?

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Re: UAP-AC-IW no POE for specific cable only

"but why would you want to do tht if I can just try and re-crimp with an RJ45 connector?"

Because in my opinion, a keystone properly punched and a factory patch cable is ALWAYS better than a hand-crimped RJ45 on solid wire. Hmm, that raises another question, are your RJ45 terminals made for solid wire? There are different kinds of RJ45 terminals, and the ones for stranded wire do not work well on solid wire.

Gregg

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Re: UAP-AC-IW no POE for specific cable only


@greggmh123 wrote:

How much space do you have inside the wall, assuming that is where the IW is mounted? The patch cable can be whatever length you can stuff inside the wall with damaging it...two or three feet.

 

In this case, due to your PoE problems, I'd stop using hand-made RJ45 terminated cables.

 

Before you do anything else, have you put your crimper onto the current terminals and given them another good squeeze? Sometimes a weak crimp can be fixed that way.

Gregg


I have just a little bit of room there but I'll check again on the 19th.

 

Well, it's just a couple of cables that I needed to hand-crimp. Everything else is through a keystone jack.

 

And no, I have not tried to do another squeeze on then but I'll try.

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Re: UAP-AC-IW no POE for specific cable only


@greggmh123 wrote:

"but why would you want to do tht if I can just try and re-crimp with an RJ45 connector?"

Because in my opinion, a keystone properly punched and a factory patch cable is ALWAYS better than a hand-crimped RJ45 on solid wire. Hmm, that raises another question, are your RJ45 terminals made for solid wire? There are different kinds of RJ45 terminals, and the ones for stranded wire do not work well on solid wire.

Gregg


Ok. And yes, I use terminals that are for solid wires, this.

 

 

 

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Re: UAP-AC-IW no POE for specific cable only

[ Edited ]

@kevindd992002 wrote:

I mean I can but then it would be very tight but I won't know for sure if I don't try. I won't be on-site until the 19th though so we'll have to put this on a hold.

 

Say there are no split pairs or any connectivity issues with the cable, what else could cause the PoE issue? What would the PoE testee tell you anyway?


Voltage drop on the wire could be a problem, due to weak crimps, poor quality cable, poor quality RJ45 terminals, corrsosion anywhere, etc.

 

If you have a PoE tester that tests more than just the available voltage, i.e., the tester can load the circuit, then you can tell directly whether or not enough power is there to run the IW. **Having voltage without a load on the circuit is rather meaningless.** For example, using a car battery tester (a good digital one), I can connect one test lead to a battery terminal, then put myself in between the other lead and the other terminal, and it will show the battery voltage just fine. However, if I am in between the lead of an incandescent bulb and the battery, it won't power the bulb, because thre won't be enough current to light it. A human body has millions of ohms of resistance from hand to hand. I laugh every time I see a TV show where they use a car battery and jumper cables to torture someone, showing a huge shock surging through the victim's body when the end of the jumper cables are touched to the person. In reality, that would do NOTHING. Eighteen years of experience as a Ford tune-up and electronics tech is how I know that, and picking up hundreds of batteries by their terminals bare-handed, without so much as one shock due to a human body's resistance. WARNING! The comments above are referring to 12V DC car batteries...do not try this on AC voltage, or higher DC voltage!

Supposedly, this tester https://www.amazon.com/WS-PoE-Tester-Inline-Voltage-Current-Detector/dp/B07PFRMH5N can simulate a powered device, and it can be used inline to see the actual power being supplied.

 

Gregg

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Re: UAP-AC-IW no POE for specific cable only

[ Edited ]

"I won't be on-site until the 19th"

Plenty of time to pick up some short patch cables!!!

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Re: UAP-AC-IW no POE for specific cable only

Somewhere in the bowels of my test kits, I have something like this https://www.amazon.com/Greenlee-Communications-1902-Modular-Adapter/dp/B000099O64 to allow testing volctage any way I need to see it.

 

I put that PoE Texas tester into my Amazon cart just for the heck of it.

Gregg

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Re: UAP-AC-IW no POE for specific cable only


@greggmh123 wrote:

@kevindd992002 wrote:

I mean I can but then it would be very tight but I won't know for sure if I don't try. I won't be on-site until the 19th though so we'll have to put this on a hold.

 

Say there are no split pairs or any connectivity issues with the cable, what else could cause the PoE issue? What would the PoE testee tell you anyway?


Voltage drop on the wire could be a problem, due to weak crimps, poor quality cable, poor quality RJ45 terminals, corrsosion anywhere, etc.

 

If you have a PoE tester that tests more than just the available voltage, i.e., the tester can load the circuit, then you can tell directly whether or not enough power is there to run the IW. **Having voltage without a load on the circuit is rather meaningless.** For example, using a car battery tester (a good digital one), I can connect one test lead to a battery terminal, then put myself in between the other lead and the other terminal, and it will show the battery voltage just fine. However, if I am in between the lead of an incandescent bulb and the battery, it won't power the bulb, because thre won't be enough current to light it. A human body has millions of ohms of resistance from hand to hand. I laugh every time I see a TV show where they use a car battery and jumper cables to torture someone, showing a huge shock surging through the victim's body when the end of the jumper cables are touched to the person. In reality, that would do NOTHING. Eighteen years of experience as a Ford tune-up and electronics tech is how I know that, and picking up hundreds of batteries by their terminals bare-handed, without so much as one shock due to a human body's resistance. WARNING! The comments above are referring to 12V DC car batteries...do not try this on AC voltage, or higher DC voltage!

Supposedly, this tester https://www.amazon.com/WS-PoE-Tester-Inline-Voltage-Current-Detector/dp/B07PFRMH5N can simulate a powered device, and it can be used inline to see the actual power being supplied.

 

Gregg


Yes, I'm very much familiar with electronics as that's what I studied in College Man Happy

 

I guess I'll need to try out some of the tips we discussed here first before I buy the PoE tester from Amazon. I'm from the Philippines, btw, and I always buy from Amazon but it takes a while for items to arrive at my doorstep.

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Re: UAP-AC-IW no POE for specific cable only


@greggmh123 wrote:

Somewhere in the bowels of my test kits, I have something like this https://www.amazon.com/Greenlee-Communications-1902-Modular-Adapter/dp/B000099O64 to allow testing volctage any way I need to see it.

 

I put that PoE Texas tester into my Amazon cart just for the heck of it.

Gregg


Sorry, but what does that modular adapter exactly do again?

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