⟐ Answered August 28, 2025 at 18:13 MST

⟐ Commented March 15, 2025 at 5:45 MST

First, I had to remove the can overtop of this area on the PCB. (I used a preheater, hot air, and a knife blade, but if anyone has any tips for this process, they would be appreciated, because it wasn't easy to get off).

While doing so, I accidentally knocked half a dozen or so components from their intended positions by poking in a bit too far. Most were just rotated, but a few were displaced entirely. I put the components back on the board the way they're supposed to go. I did lose one capacitor and wasn't sure of it's value, but it was one of the larger ones, so I went on the larger side and went for 10nF.

Reassembling and plugging the phone into power, a USB volt/ammeter shows me that it's drawing 0 amps at 5V. Using a multimeter, I found that certain capacitors were showing as shorted. I attempted voltage injection (1V, up to 550mA) with a thermal camera, but didn't see any hot spots.

I did knock the chip with 29 on it off the board earlier, so I removed it, but the short didn't go away, so I put it back and kept removing components until it did. Checking the PCB layout, the component that was showing as shorted was only connected to 3 or 4 other components, so there weren't many to eliminate. Strangely, two components that I removed were both showing as part of a shorted rail but were not connected to the same places at all (using a PCB layout viewer of the 7 Pro). I removed them both, and the short was cleared. I guess multiple components having shorts is possible. According to the PCB layout, these components are related to the rear cameras, so they shouldn't be relevant for booting.

Now that the short is gone, I plugged the device back into USB power and it draws a steady 0.13A, but does not turn on and I can't even access EDL mode, which is a bootloader on the SoC itself, so it doesn't rely on the NAND flash. There is also a high-pitched coil whine sound that goes for 2-3 seconds, very briefly stops, and starts again. The current doesn't change when I prompt the phone to boot with the power button (or short what I believe is the power key testpoint to ground).

From factory PCB layout around NAND region:

My board after removing components to clear the short:

Another angle of the NAND region. Yellow = 29 chip I displaced. Blue = components removed to clear short. Red = general area in which chips got bumped

How can I diagnose this issue further? Thanks

I desperately need to know the component and the value of this unit so I can replace it in a OnePlus 7 Pro mainboard.​

1) Any idea?​

I suspect that it might very well be either a 2.2 uF capacitor, or a 1 uF. It is connected to the VDD N-FET pin of a Samsung UFS.​

So, I think that it is a Samsung UFS V_DD N-FET pin 0201-sized grounding ‘MultiLayer Ceramic Capacitor’ (MLCC).

2) What would happen if I installed the 1 uF while a 2.2 uF capacitor was required, or vice versa?

Thank you so much in advance!​

I have not been able to find a OnePlus 7 Pro schematic, but have found one of the OnePlus 8 Pro with a Samsung KLUDG4UHDB-B2D1 UFS-3.0 (listing a 2.2uF); Oneplus-6 UFS 2.1 (listing a 1 uF but in parallel), which is most probably Samsung’s KLUDG4U1EA-B0C1 which the OnePlus-6T has which is also UFS-2.1, OnePlus-6 has UFS 2.1 2-LANE 64 GB / 128 GB / 256 GB editions, while OnePlus-6T has 128GB / 256GB editions, and there is only a half year release date difference ; and a OnePlus-3T with Samsung’s KLUCG4J1CB-B0B1 UFS-2.0 (stating that a 1 uF one should be used in case of a Samsung UFS). The OnePlus 7 Pro has a Samsung KLUEG8UHDB-C2D1 UFS-3.0. This makes me to conclude that it is most probably a 2.2 uF. I have added attachments of the schematic diagrams I could find. I have highlighted the V_DD I_Q line.

Any thoughts on this?

⟐ Commented January 15, 2025 at 15:33 MST

I'm trying to get to know what this component is (resistor, capacitor, or something else?), and what value it has (e.g., resistance [Ohm], or capacitance [F]).

At first I was quite sure that it is a capacitor because of it's coloring, and thought it read around 0.8 pF, but now I am doubting, and the 0.8 pF reading is achievable without the component, just by bringing both lead ends closer together on parallel capacitance measurement mode on 100kHz.

Maybe you can help me out, as I have no idea how to measure it.

The readings are quite all over the place.

This video is me trying to measure it on capacitance mode on a DER EE DE-5000:

https://youtu.be/yuof1fu6fRU?feature=sha...

All help is very much appreciated!

Resistor measurement attempt:

https://youtu.be/xAOom--sgwg?feature=sha...

More close-up photos of the component: https://imgur.com/a/s3hCpFz

Photos of location of the board it came from:

A OnePlus 7 pro phone mainboard, in the right bottom corner of a UFS chip.

I took two pictures, in the second picture you can see me pointing at the location with a set of tweezers.

https://imgur.com/a/Lm4qOQX

If you have any idea how to determine what this component is and what it's value is I would be extremely thankful! 🙏

Any suggestions how I can measure this component? I bought Probe Master 8152 spring loaded micro-tip test leads, but those do not seem to work with the EE DER DE-5000.

https://eleshop.eu/probe-master-8152-spr...

I just got the last (fourth) phone last week. I tried it and worked fine. Then disassembled it, still worked perfectly fine. Then disassembling the metal cover shield. Then testing it again, and still works fine.

Then carefully removing the component with Kapton tape over the other components, no clean flux and a hot air desoldering station to get the 0201 component off the phone.

The phone doesn't work without this component.

I looked up YouTube videos of mainboard schematics of the OnePlus 7 pro and found that it most probably is involved as a power-on line. As I tested with the second and third phone I got, I did exactly the same as described above and they wouldn't turn on without this component.

Does this mean that it is likely not a decoupling capacitor?

Some more info and pictures of it I was able to find via Borneo Schematics:

I'm struggling figuring out what component is on the right bottom of the top chip, it's greyish, but I am not able to measure it. https://imgur.com/a/oNTbvQO Perhaps you know? Thank you so much in advance!

I've added more pictures of the component I am trying to figure out over here: https://imgur.com/a/DUlGWZJ

Because it is grey-ish, is it a capacitor, or is it maybe a ferrite bead?

⟐ Commented January 07, 2025 at 13:36 MST

⟐ Commented November 28, 2024 at 11:17 MST

⟐ Answer edited August 31, 2024 at 9:00 MST

⟐ Answered July 07, 2024 at 22:15 MST

Forced restart is not working. Sometimes it can show android and oneplus logo for a few seconds before going to completely dark again. During those times, there is a small chance of showing banding-pattern lights on the screen with those logos.

I have tried a local repair shop, where battery and screen are replaced for a test.

Nothing really changed.

Motherboard malfunction is suspected.

I don't need the phone come back to life right now. (It would be good though)

But really would like to at least salvage some data from its storage.

Is this possible?

Thank you.

⟐ Answer accepted March 21, 2024 at 6:58 MST

From watching teardowns, I have no idea why only one part of the screen would be dead. I thought it might be an issue with the optical fingerprint scanner, so I tried taking that out, but still the same problem. Any idea what I might be able to do to fix this?

EDIT: forgot to mention, I’m also getting “ghost touches” in around the middle of the screen, between the working half and non-working half. Happens mostly on the left side of the screen. Don’t know if that helps to figure out what’s wrong/broken.

⟐ Answer accepted January 22, 2024 at 20:04 MST

<app_name> failed to start several times. Restore it by clearing history?

After several reboots, even the lockscreen UI stopped working, flickering the wallpaper image for a few moments every once in a while and going back to pitch black. Pressing volume keys does nothing, however holding the power key brings up a menu with: lockdown, power off, restart, and "Bug report - 12 (SKQ1.211113.001)". The phone also shortly vibrates every two seconds.

While the phone is plugged into PC via USB and powered on, it shows up as "SM8150-MTP _SN:<random_string>" with a caption "Driver is unavailable" in the Windows devices list. It also connects to my Wi-Fi router.

Any ideas what it is, why is that, and what to do?

⟐ Commented August 15, 2023 at 9:35 MST

⟐ Commented June 20, 2023 at 15:58 MST