Please Help - Unknown SMD component need replacement

Thread Starter

GKgas

Joined Sep 1, 2019
2
Hello All.
New to this forum, Newbie in electronics as well... :/
anyway, my name is Chris!
Nice to meet you!

So, After a thunderstorm during last winter, My security IP camera was stop working!
It was powered through POE 48volt and after I took apart the main PCB I've noticed this:
upload_2019-9-2_3-25-3.png
https://prnt.sc/p0bbxu

good thing is that the component next to this Looks OK and must be the same like the blown one.

so, I've unsolder the blown component and a three contact pattern was revealed below it.
(I've also found some strange marks on that brown component, pointing with the red arrow. do you think is also blown??)
upload_2019-9-2_3-26-45.png
https://prnt.sc/p0bdqf

I've strangle my brain more than 2 months to find out what this little black square is.
Local electronics store has no idea. nor anyone of my friends....

Can you help me find what is?

Thank you a lot!

xx
 
Last edited by a moderator:

ronv

Joined Nov 12, 2008
3,770
Hello All.
New to this forum, Newbie in electronics as well... :/
anyway, my name is Chris!
Nice to meet you!

So, After a thunderstorm during last winter, My security IP camera was stop working!
It was powered through POE 48volt and after I took apart the main PCB I've noticed this:
View attachment 185195
https://prnt.sc/p0bbxu

good thing is that the component next to this Looks OK and must be the same like the blown one.

so, I've unsolder the blown component and a three contact pattern was revealed below it.
(I've also found some strange marks on that brown component, pointing with the red arrow. do you think is also blown??)
View attachment 185196
https://prnt.sc/p0bdqf

I've strangle my brain more than 2 months to find out what this little black square is.
Local electronics store has no idea. nor anyone of my friends....

Can you help me find what is?

Thank you a lot!

xx
One can only guess. But if I were to guess, I would guess it's a TVS diode. In which case you can remove it and see if it works.
Not sure about the other component, but it looks like a match for the similar component below it.
 

Ylli

Joined Nov 13, 2015
985
Well, the strange marks on the capacitor are burns from the arc that flashed across it. The TPS23750 is a POE interface and an DC/DC converter. Data sheet here: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2ahUKEwickJjUm7HkAhXQna0KHWbCBJoQFjAAegQIBRAC&url=https://www.ti.com/lit/gpn/tps23750&usg=AOvVaw2Dnw7XYQw1FiAuKb2y8pBk

If you trace out the circuit, you may get a better idea what the fried component is. I suspect it is a MOSFET. Chances are that many of the devices on that board were taken out by the power surge - just bite the bullet and buy a new one.
 

MisterBill2

Joined Jan 23, 2018
7,297
My guess is that the device removed is a transistor, but it may also be a diode of some kind. And there is no reason to believe that it is the same as the one next to it, because there are package styles used for MANY devices that work at a similar power level and have 2 or 3 connections.
So to get an answer that is better than a guess you will need to trace out the circuit a bit, although locating a circuit diagram is a better choice.
 

Tonyr1084

Joined Sep 24, 2015
5,234
Others have already covered what I might have answered. As for the burns across the capacitor - I'd bet there are far more blown components than just the one (or two) in hand.

Security cameras aren't cheap. Unless you got a cheap one. If you want to try and repair it for posterity sakes - go ahead. However, I suspect you're going to discover that more than just the one or two components have been damaged. And without the numbers on the face, 1) you can't know for sure what the component is and 2) you won't be able to find its replacement.

One final point - for a "Newbie" removing a surface mount device is pretty impressive. My first go-arounds with SMD's usually ended in disaster. Lifted pads and damaged components. But hey! Just because I screwed up doesn't mean everyone else must.
 

MisterBill2

Joined Jan 23, 2018
7,297
OK, I missed the part about it being a security camera. Check the warranty is my suggestion, and if it is still in effect put the part back, re-assemble it, and send it back. Even distant lightning can do a whole lot of damage. I have experienced that first hand.
 

Tonyr1084

Joined Sep 24, 2015
5,234
One other thought, concerning the similar component right next to it - - - it could be the complementary part. What I mean is if one is an NPN transistor the other could be a PNP. Or if it's an N-type FET the other could be a P-type. Possibilities are endless.
 

Thread Starter

GKgas

Joined Sep 1, 2019
2
Guys, thank you all for your quick answers!
I think you all right, the thunder that hit my house was extremely powerful!
I've never seen anything like this before, so, I guess everything must be burned out.

also warranty is void because the RJ45 plug was smokey and smell like burned plastic
so they directly told me that it's my fault cuz I forgot to connect the Ground protection properly... (although it was connected by my IT)
anyway....
Too sad, Was my only 4K IP camera...
any way, I'll try to buy a new one on black Friday.. lol

Thank you all again!
xx
 

sagor

Joined Mar 10, 2019
283
I agree with Tony, a EMP or Lightning strike into that device probably blew more than just one component. Fixing it may be a long and frustrating exercise. Best to simple replace the device, and install some lightning protection on the POE feed.
 

MisterBill2

Joined Jan 23, 2018
7,297
Guys, thank you all for your quick answers!
I think you all right, the thunder that hit my house was extremely powerful!
I've never seen anything like this before, so, I guess everything must be burned out.

also warranty is void because the RJ45 plug was smokey and smell like burned plastic
so they directly told me that it's my fault cuz I forgot to connect the Ground protection properly... (although it was connected by my IT)
anyway....
Too sad, Was my only 4K IP camera...
any way, I'll try to buy a new one on black Friday.. lol

Thank you all again!
xx
Given that response to your request under warranty, I suggest a different supplier. And in a case like that a ground would not help, anyway.
 
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