Hacking Feedback Hardware Cut trace - 0mv batt - Can't boot to OS

[ThisFoxLikesTacos]

Hello.
While installing a Picofly Lite RP2040 and using the alligator clamps to hold the PCB one of them lost the rubber grip and the clamp scratched into the PCB. (See the attached photos for reference.)
I am able to boot into hekate and I have taken backups of the eMMC NAND, and prod keys. I confirmed via nxnandmanager that the backup is clean.
While in Hekate the battery shows %0 and 0mv across in batt info readings, and from what I've gathered there is a battery safety test when booting HOS that would cause it to not boot.

Atmosphere gives the following error when trying to boot:
A fatal error occurred when running Atmosphere.
Program ID: 0100000000000005
Error Desc: std:abort) called (Oxffe)
Failed to save report to the SD cardt (00000202)
Press POWER to reboot.

Trying to boot OFW using Power & Vol +/- leads to a black screen, need to power off manually. - Unplugging the modchip does not allow the console to boot to OFW.

I think the cut traces are likely the problem and not something to do with the modchip install itself, I went back and checked and refreshed all of the solder joints.
I've done a lot of looking into this on the internet and I have the board layer viewer website as well as openboardview that I have been using to try to track what the trace goes to.
But I just don't know how to put everything in to practice to identify and fix the issue.

Despite all of this, if I am on the wrong path and you think I should be looking into other things just lmk! Any help would be greatly appreciated!
Thanks!

 

[thesjaakspoiler]

While in Hekate the battery shows %0 and 0mv across in batt info readings, and from what I've gathered there is a battery safety test when booting HOS that would cause it to not boot.

Yes, that is also my understanding. I have never tried it but I read it also applies to the CFW.
The CPU communicates over I2C with the battery management chip.
If those traces are interrupted, it has no idea about the state of the battery.
To prevent you Switch turning into a big fireball due to a bad battery, Nintendo just prevents it from bootinh.
Sometimes one of the 2 pull up resistors of the I2C lines near the shield are missing.
Also maybe check for damage round/under the metal shield as that is also a location things could have gone wrong.

Severed traces can be repaired with fine coil wire but just scratch them a bit at the end to see if they are really severed.
Most of the damage looks like damage to the green top layer but I could be wrong.

That atmosphere error can also be messed up system modules, a bad atmopshere installation or folders marked as read-only.
Also strange is the fact that it cannot write to the SD card.
Try dumping BOOT0 in Hekate to see if you get any errors.
If you get errors then there might be something wrong with one of the lines, but then Hekate should also not boot in most cases.
If you don't get any errors, then try installing Atmosphere without any additional modules like the Tesla overlay.

 

[ThisFoxLikesTacos]

Yes, that is also my understanding. I have never tried it but I read it also applies to the CFW.
The CPU communicates over I2C with the battery management chip.
If those traces are interrupted, it has no idea about the state of the battery.
To prevent you Switch turning into a big fireball due to a bad battery, Nintendo just prevents it from bootinh.
Sometimes one of the 2 pull up resistors of the I2C lines near the shield are missing.
Also maybe check for damage round/under the metal shield as that is also a location things could have gone wrong.

Severed traces can be repaired with fine coil wire but just scratch them a bit at the end to see if they are really severed.
Most of the damage looks like damage to the green top layer but I could be wrong.

That atmosphere error can also be messed up system modules, a bad atmopshere installation or folders marked as read-only.
Also strange is the fact that it cannot write to the SD card.
Try dumping BOOT0 in Hekate to see if you get any errors.
If you get errors then there might be something wrong with one of the lines, but then Hekate should also not boot in most cases.
If you don't get any errors, then try installing Atmosphere without any additional modules like the Tesla overlay.

I am glad you mentioned that the damage looks superficial on the pcb. Because I felt the same and I didn't want to try to repair something that wasn't broken in the event that it was something else causing the faults.

I have been able to dump Boot 0/1 as well when doing backup/dumps. Both SD card and eMMC show up in Hekate without any errors and all of the read outs look okay from what I can gather.

Supposedly I was able to create an emuNAND but as with sysOFW/CFW I am not able to boot.

I will take your advice to check to see if the traces are split fully or not, if they are I am sure I can repair them, but I wasn't sure if there was any other way I could tell for sure.

I'll make up a fresh SD card to test out. The switch has fw 18.0.1 (or 18.1.0 idr), would using the newest atmosphere cause issues that require me to use an older version?

I will double check around the CPU again to be %100 sure. Is it possible that one of the SP1/SP2 points for the picofly could be causing this issue? I have also wondered if I haven't removed enough flux even though I have tried to get most of it. Have you seen anything like that before?

 

[ThisFoxLikesTacos]

check for damage round/under the metal shield as that is also a location things could have gone wrong.

Hey I think you got it! I took another look under the scope and after scanning that area for a bit I found this little ding at the bottom left of the apu! I am glad I was able to find it, thank you! It looks less shiny than the others so I am assuming that its gone all the way through and thus severed the connection.

With it being such a small indent I should be able to just scratch off a little of the top layer on either side and use a dab of solder to bridge the connection correct?

Also maybe check for damage round/under the metal shield as that is also a location things could have gone wrong.

Severed traces can be repaired with fine coil wire but just scratch them a bit at the end to see if they are really severed.
Most of the damage looks like damage to the green top layer but I could be wrong.

Okay, I checked the resisters under the cpu/apu, there is nothing wrong from what I can tell. I also scanned over the board again and I didn't find any other damage.

I attempted to scratch away some more of the trace and bridge the connection using solder. It looks like it should be working but I am still getting the same problem. (No boot past Hekate, OFW/CFW/SYS/EMU. 0mv no battery stats in Hekate)

I am at a loss. I'm thinking trying to repair with some 30AWG enamel wire instead of just solder. Or trying to repair the other traces as well.

Any other ideas? I would really appreciate any advice. This is a project that I am doing for a customer and I need to have it finished two weeks from now or I am SOL and have to replace the switch.

Thanks for any help!!

I was also thinking about removing the whole chip and ribbon cables but I didn't want to do that if it wasn't going to be the cause of the issue. Would you recommend I do so?