Samsung Galaxy S7 Edge - No Power - Not Charging - Mainboard Repair - iRefab

Do it yourself for cheap! How to diagnose, source and replace a Samsung Galaxy S7 Edge, model G935F mobile phone mainboard that has no power and is not charging. Plus some tips and tricks along the way. Full detailed diagnostics with service manual repair procedure, guidance and notes.
Something not working? Can't repair it yourself? Don't throw it away just yet! Contact us and we can do it for you (mail in repairs). Contact us through the website below:
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Service Manual for Samsung Galaxy S7 Edge Model G935F:
irefab.co.uk/downloads/
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[@mihpop9733]

What is the normal temp of those shorted chips though?

[@Tahsin_Hussain]

I have around 10 of S7 Edge at home with same problem. These were my child's phone which was broken. Previously I changed the whole main board in one of them and it worked. Can you tell me why this problem occur at the first place. Also, I want to sell these phone for parts. But my worry is if someone can fix it and find any sensitive family photo or video in it. Can you tell me HOW CAN I DESTROY or DELETE ALL PHONES INTERNAL MEMORY DATA from a S7 Edge which does not turn on?

[@irefab]

@Tahsin_Hussain to answer your first question the S7 edge is a very old phone now and what happens is the solder balls under the CPU become dry and brittle over time and with heat. Any heavy knocks on the phone and they come out of place and short out the CPU. When this happens the phone essentially becomes a brick. It’s a common problem with the S7 edge and well known about in repair circles. Regarding your second question I don’t know how you can erase data if the CPU is shorted as there is no way to interface the board. If the screens are good just sell them on and throw the boards in the bin or keep them for components/parts. You can also list them on eBay as non working practice boards for people learning to micro solder. Hope this helps 👍

[@sinitration]

Good vid. Any advice for my s7 edge with no charge, no power, and no face notification LED or vibration? At this point the only sign of life i get is when i connect the micro usb cord the LED rear facing tourch flashlight flickers on and off rapidly. Prior to that i was able to apply pressure in a specific area of the phone and get it to almost fully boot before freezing on the AT&T boot screen

[@irefab]

Could be the be the balls under the power management chip, could be a CPU short. You will need someone who has a thermal camera to check it out. Best to get down to a local reputable repair shop. They should be able to confirm that for you. If it’s a CPU short, it’s time to move on. Power management IC is doable 👍

[@sinitration]

@@irefab Thanks for the reply. The Power management IC section heats up considerably when the LED flashlight starts flickering. I'm pretty sure it's the top section of the PCB, although I suppose it could be whatever is directly underneath it on the backside. I have access to a soldering station with hot air, would it be jumping the gun to pull the PM IC? Thanks again.

[@irefab]

Underneath the video there is a link to a service manual. Download that first and follow the procedure to eliminate all the other components in the power supply chain. The you can try pulling the PMIC and re-balling it. Failing that you could try replacing it with a new one. But you have to be careful as the CPU/RAM is directly underneath on the backside of the PCB. Too much heat and you will melt the balls under the CPU. If you can’t get hold of a thermal camera try the freeze spray method to locate the source of the heat first before you start taking things apart. At least that will give you a better idea of the location of the fault.

[@sinitration]

@@irefab great info. I tried a brief low temp (500~°F) reflow on the pmic and had small luck getting the screen to display the Samsung and at&t logo but shortly after the flashlight led started to go crazy when connected to usb. Hopefully I didnt already bridge any solder balls on the cpu area. I'll be check out that service manual shortly. Thanks again I'm hoping for the best

[@giuseppealoisio2507]

hello.... where do you find service manual? could you share the sorce? thanks a lot. why didn't substitute the U7011?

[@irefab]

Hello Giuseppe, CPU Short so no point substituting U7011. When you have CPU short, no point wasting time with anything else, trust me I have worked on too many of these boards. Regarding the service manual, sure no problem, here's the link for you: www.irefab.co.uk/download_files.html

[@DeanCyber]

Hi, thanks for the video. Is there any way to recover the data from the board ? I have similar issue with my old s7 edge and i was wondering if i can recover the data

[@irefab]

Hello @DeanCyber . The CPU is tied to the storage chip and cannot be replaced. If the CPU is damaged data cannot be retrieved from the storage chip. The CPU contains the information to un-encrypt the data on the storage chip.

[@DeanCyber]

@irefab The thing is I don't know exactly where is the issue because I don't have a multimeter nor even psu to troubleshoot, any advice? I think the best is to replace the board, i found one in aliexpress for 20£

[@irefab]

@DeanCyber The Galaxy S7 edge is known to have a common problem and that is the CPU short. It can happen if the phone is dropped and as they are getting older now the solder balls below the CPU dry up and any knocks can send them out of place or short them out. We can tell if it’s a CPU short by inspecting it with a thermal camera like I showed in the video. Any respectable repair shop should be able to tell you if the CPU is shorted or not if they have basic test equipment. Thats not very hard to figure out. In the old days we could access the data on the drive in other ways but since the Galaxy S6 came out Samsung now encrypt the data on the drive and you cannot access it if the CPU is not working as far as I am aware. As I say, if the issue was any other chip on the board, we could possibly fix it but trying to fix a CPU short is almost impossible in my opinion. Just replace the board and get as much life as you can out of the rest of the phone.

[@badalamour1876]

nice video man, Customer lost his/her data💔💔

[@irefab]

Thank you for watching the video Badal 🤲🏻 Data recovery costs $$$ and I did offer the customer the option if they wanted it done through a third party. But they said it’s fine as they had most of the data backed up to google 👌 So I got lucky on this one 👍

[@RoadRunnerMeep]

I have no power at the inductor but power at the capacitor but 5v at the cap? directly below it

[@irefab]

No power at the inductor, replace the Sub PBA as referenced in the service manual. You don’t have to remove the old Sub PBA to do this, just take a working one from another phone or buy one from eBay about $3 or £2. Attach it to the main board and test to see if you get 5v at the inductor. If you do problem solved, if not keep following the steps in the service manual to find your faulty component and replace. Hope this helps 👍

[@stephenainsworth629]

Is there anyway I can recover my data

[@irefab]

If the CPU is damaged like in the case of the video, there is no way to recover that data. The data on the storage is encrypted and the key to unlock it is on the CPU. No CPU, No Data …

[@nicknick3136]

At 3.46.. you say why we dont get any voltage here? you disconnected the battery.. thats why..check it with the plug connected..

[@irefab]

Hello Nick, and thank you for watching the video. Just before taking the measurement I said “let’s switch the power on” and on the screen lower right corner you can see that the phone is pulling 600ma. The phone would not be able to pull current if the power was not connected. So the plug was connected when taking the measurement but you can’t see that in the video. Hope that clears up any confusion 👍

[@nicknick3136]

@@irefab Ok.. so you connected the power supply somewhere on the pcb.. Was more clear if you had that part on video also.. or telling.. ,the supply is connected on the board directly.. ( could be helpfull for other viewers where these points are ) Thanks for your quick response..

[@irefab]

Not directly to the board, just connected the USB cable and switched on the power supply and the power supply output is shown on the screen 👍

[@nicknick3136]

@@irefab Thats of course the other possibilety.. all clear now.. 💯