v1 unpatched only boots OFW if install sysMMC after RCM and launch via Hekate

[howardc64]

Have a v1 that shows black screen after power on or inserting Nintendo charger. No shorts anywhere on system. All first stage boot voltages good. Doesn't boot from SysMMC. Reflowed eMMC 2x without any improvement. Also can not enter RCM mode except for the following sequence

Enter RCM mode

1. If plug-in battery with sysMMC disconnected will go to RCM mode of course.
2. If plug-in battery with sysMMC connected, can not enter RCM mode with my RCM trigger (Right joycon connector ribbon cable soldered 10k resistor between pin 7+10)
3. If after #1, then connect sysMMC, can boot Hekate, launch Stock OFW (16.0.1) and Atmosphere fine and works. After powering off OFW, can get into RCM mode with my RCM trigger. However, if try to boot OFW without going through RCM, can not trigger RCM anymore (until redo #1.

Fuse Info

Burnt Fuses (ODM 7/6) : 16 - 0 (HOS: 13.2.1 - 14.1.2)

Launch Hekate (6.1.0) Atmosphere 1.6.2

After #3 sequence above, can RCM and Hekata launch Atmosphere. Everything works fine

Launch OFW on sysMMC

After #3 sequence above, can RCM and Hekate launch OFW (16.0.1). Everything works fine.

Updating + Changing OFW

OFM 16.0.1 has an update, if update that, update eventually reboots and just stuck on blank screen. Booting OFW and Atmosphere 1.6.2 via Hekata both get unknown pkg1 20240207... (020724 is release date for 18.0.0) Clearly need to wait for new atmosphere release to handle the new firmware.

Have backup so rebuild OFW to 16.0.1 with system wipe. Same boot to black screen problem. Same RCM mode behavior. RCM->Hekata->Atmosphere/OFW launch and works.

Built 14.1.2 OFW (per burnt fuse info). Same boot to black screen problem. Same RCM mode behavior. RCM->Hekate->Atmophere/OFW launch and works.

Built 17.0.1 OFW. Same boot to black screen problem. Hekate->OFW didn't boot successfully initially (Shows battery charging icon and then black screen (I think goes to RCM). However Atmosphere did boot and setup 17.0.1 and OFW booted fine after that.

Additional Problem

No sound in Atmosphere/OFW. Not sure this is due to connecting sysMMC after RCM in #3 sequence or some other HW problem.

Fuse Matching Problem?

This is son's switch and he said he triggered an update and switch eventually just stopped responding. Presumably it rebooted at some point and is hitting the behaviors I am now seeing. I don't know what OFW version he was on and what the upgrade was to.

Seems like #3 suggest there is fuse check prior to RCM? If so, it explains why I can get many things running with this sequence but not if sysMMC was connected while powering on.

Also it seems no matter which OFW is installed, the above fuse pattern is the same. I guess since the switch can't launch OFW by itself and always via Hekate, fuses are never updated. Anyway, the fuse matching OFW 14.1.2 also can not boot on its own so something else seems to be prevent the sysMMC boot.

17.0.0 Save File Management

Also read about OFW 17.0.0 save file management issue (this switch sysMMC was recovered once 2-3 years ago) and fix by Atmosphere 1.6.1. After running Atmosphere 1.6.2, same problems persist

=====

Any other ideas I can try? Seems like its a fuse mismatching problem? If so, then what OFW should I rebuild other than noted by the burnt fuses? Is inability to RCM without disconnecting sysMMC but then connect sysMMC and able to RCM->Hekata->Atmosphere/OFW show a specific problem?

Considering trying 18.0.0 need to wait for newer than 6.1.0 Hekate. Although since I did a couple of updates that went to black screen after update reboot and shows pkg1 is from 18.0.0. Maybe its worth a try. But if it doesn't work, then have at least lost Hekate until it can handle 18.0.0

Am newbie so can't post pics/links...

===== UPDATE =====

Post automatically merged: Mar 28, 2024

No sound and when TV has no signal when docked with RCM->Hekate->OFW so perhaps P13USB is suspect even though no shorts.

 

[thesjaakspoiler]

Seems like #3 suggest there is fuse check prior to RCM?

No, the fuse check isn't performed when entering the RCM mode.
So that can't be it.
I have never tried a resistor between those pins but some posts here suggest that a resistor in the controller causes the problems you describe.
So may try a separate jig?

Since you can boot into ofw, it doesn't sound like the emmc had gone bad.
I vaguely recall that Hekate can check that for you.

 

[howardc64]

No, the fuse check isn't performed when entering the RCM mode.
So that can't be it.

Thanks for confirmation.

I have never tried a resistor between those pins but some posts here suggest that a resistor in the controller causes the problems you describe.
So may try a separate jig?

The RCM trigger issue turns out to be

If true cold boot (say just plug in battery), have to hold vol+ and pwr for a long time (say 20s?) I guess something (BOOT1?) need to shutdown and truly boot from scratch to enter RCM?

Any power off via touch screen can be triggered into RCM instantly

When running OFW (via Hekate) If hold down pwr button for long time. It will shut off and require a long time to trigger RCM. Presumably was completely powered down.

Since you can boot into ofw, it doesn't sound like the emmc had gone bad.
I vaguely recall that Hekate can check that for you.

Yes, eMMC appears to be good enough to run Hekate->Atmosphere/OFW
Internal eMMC Info looks good. eMMC Benchmark shows good results on all 3 passes.



=====

Current status is

• OFW 17.0.1 installed. Doesn't boot by itself like all other OFW versions tried (16.0.1, 13.2.1, 14.1.2)
• Any cold boot (replug in battery, hold pwr button until screen turns off) require longer time to trigger RCM. I'm guessing this is normal.
• Hekata can launch OFW. OFW works perfect. Turn off OFW and trigger RCM again instantly.
• Sound magically started working after leaving Switch in OFW sleep overnight and on charger.
• Dock works reliably as well with Nintendo HDMI cable.
• Downloaded Mario vs Donkey Kong Demo from eShop. Runs fine in with/without dock
• If system update from from any OFW, will install update, reboot and won't boot up again. Hekate->OFW will get pkg1 20240207... error indicating OFW 18.0.0 is installed. Rebuild NAND with < 18.0.0 OFW to recover from this.

So pretty much everything work as expected except can't boot OFW on its own and fuses stuck on old.

Post automatically merged: Mar 29, 2024

Randomly decided to install OFW 14.0.0 (version matching fuse pattern) and switch now boot OFW without going through RCM.

However, system update (automatically choose 18.0.0 from pkg1 info later seen when booting Hekate) will go through reboot and fail to boot. So something about recent OFW releases (17.0.0 had the save file mgmt brick OFW issue) that seems doesn't like previous rebuilt NAND switches.

A few things of note for someone that doesn't do these NAND rebuilds all the time and unfamiliar with timing of things

• Didn't know about the --no-autorcm no NAND rebuild, so got fooled thinking rebuilt NAND wasn't booting OFW on its own.
• Cold boot (plug-in battery, holding power to shutdown OFW) takes awhile to trigger RCM compared to powering off by touch screen options.

Anyway, I'll wait until Hekate/Atmos support latest OFW before trying again. So doesn't look like HW, rather latest OFW is causing some bricking.

14.1.2 worked as well (match fuse pattern). But no > 14.1.2 OFW rebuilt NAND will boot without RCM injection. All OFW system updates to 18.0.0 fails.

 

[howardc64]

Fixed. Reflowed SOC+DRAM. Link here for future

https://gbatemp.net/threads/v1-cant-run-higher-than-fuse-stock-ofm-without-rcm.652529/post-10390387

 

[nabbyboy]

My DM was about this topic.