Amcrest Forum

Hi all!

I inadvertently plugged a 12v 2amp power supply in the camera for about 20sec.
I does smell a bit like burnt plastics
It no longer rotates on startup nor shows up on the network.
I probably fried something... I'm not too bad with electronics, any one managed to open it up and changed the blown part(s)?

It is an old camera, but I like the firmware's API and it was not in a high value location so the 2MP was well enough.

thanks!

Well that wasn't easy to do.. The connection for the cameras is much smaller then normal 12v camera..

Anyway to take apart you will remove the 4 feet pads, then 4 scews under them. Then once you take the bottom off using spudder or something not to damage the preaser fittings.. There will be a full sized PCB with 1 scew that will be holding the board in. Disconnect the wiring for Motors, Mic that you can see from bottom and then take out the screw. Then you will need to remove other motor wiring, camera ribbon cable and can't remember might be another cable under there it has been a while since took the PCB out.. Anyway that will give you access to the main PCB on both sides and sure the damage will be very evident using 12v on a 5v device.. Might have even burned up some traces in the circuit for it.. Hard to say. Would be very lucky if only a protection diode was the issue.

So maybe take a picture of the PCB I would be interested in seeing what type of damage it would show after 12v connection..

Personally if there is no TVS or Fuse and something small and easy to find and replace the cameras are cheap enough I wouldn't jump down to large of a Rabbit hole for the camera.. Maybe some caps and fuse, diode TVS or other and maybe a voltage regulator with clear markings but much more then that damaged it might have gone clear to the CPU then no ability to repair that type damage for these cameras..

Here is top and bottom picture of one of my 841W. This camera is from 2016 as you can see in PCB silkscreen

Yeah, the 12V power supply was from an old Dlink router. I do not know for the life of me why that power supply had a 5v barrel connector.

I will open it and post a picture. Maybe there is a power converter like an AMS1117 or something. Those are easy to replace. I agree I would be very lucky to have it working again... we'll see

Thanks for taking the time to answer!

I don't see anything wrong on the PCB...

https://imgur.com/vSF8XbT
https://imgur.com/Nl5dhnR

Well one thing missing off that 2018 cameras is what I am guessing is a 6v 50amp protection diode. If you look at your PCB and mine from 2016 you will see next to the input jack is a 0Ohm resistor. On mine it has what might be a Protection diode that has some Marking that looks like a part form Little Fuse because it has LF on it.. However the marking don't come up with anything that I could find.. 6ej50 But could be something like the SMBJ6.0 TVS or SS54 or ss56.. Odd they left it off the newer 2018 model but had it on the 2016 version.. I will have to go look at one of mine from 2018 and see if it also has that part missing.. I would test the 0ohm resistor make sure it is still intact.. But I am sure it is going to be worse then that seeing no protection diode in your PCB next to the power. Next will want to also check the Caps that are there, While they do look good and didn't explode as normally can with wrong voltage issues.. Looking good and being good are 2 different things.. ESR meter for testing in circuit as most meters might fail in circuit testing because of other parts in the circuit.. I can not see any of the tracks so hard to know if there is any track damage but again something that would be normal for an overvoltage type event..

Wow interesting, my 841 from 29 week of 2018 also missing the part.

Very interesting. Why the downgrade, if not for economical costs (aside from the work $$ to design and remove the circuitry)

My electronic skills are limited. Probably better to bite the bullet and buy another one. They are cheap.

Nonetheless, I will keep it as a side project (in the huge side project pile lol)

So, if you happen to have a multi meter with Diode mode, set and test the mini led that is on other side of reset button. Ground probe at the rear, my guess is for starters that green led is dead. Testing will result in a value but the led will not lite. Yet testing the one on ethernet side *Red* will lite. My guess is that it is clamping to ground.

So I might have made a mistake lol but without making sure I had a camera for testing. I have over a dozen 841s yet only 1 is like yours and before verification that I had a second one of like format I blew up my camera in same format as yours lol.

Why it matters. Well I wanted to confirm if camera was good but I am not sure it is or isn't because connecting the camera to another 841 that works I don't get a picture, just a white screen. So not sure if the cameras being different year format if camera might be wired different.. I tested it on 3 different 841s all older with diode protection as the picture I posted above. Anyway all resulted in white screen only so either camera is dead or need a 2018 version for better testing..

What I did find so far is that the led has died..again seems only green side as the red lites. Outside the led I don't find anything wrong with the circuit so far. But I also have a bad input so will change out the connector with just some wires to my power supply. When I connected my bench power supply to the camera the 12v dropped to 2.5v and 3amps. So should have killed something that would show but didn't. I have a replacement led so will replace and see if that restores camera. I have it all apart seeing wanted to check camera, nothing looks damaged on there so might just be led.. if I can remove the led without damaging it I will install and let you know. Keep in mind the led is very small and would require a micro tip like my fm-2032 t30-D06 or I or J on my HakkoFx951 it might be very difficult to replace. Normal handle with c1 tip might work if a tip you use often. Picture shows normal solder most people use on left lol and the one on the right I use most often and you can see how small the led is compared to the 2 solders.

Testing all other boards the green led lites but now that I killed the camera same way as you say you did at this point only fault I can find. Will report back after replacement. My issue is not sure if it was glued down and if it was the removing would damage most likely and not sure where to source a new one. Using low melt solder is best way to remove but with out datasheet hard to know it's heat tolerance.