unpatched switch emmc init failed

[james28909]

would like to say i am completely new and have tried to spend a few days reading and i am at the point where i need to decide what to do because i am unsure if it is the emmc or the apu or ram or what...

i have a switch here that i got in trade for doing some work for someone, i am able to boot the switch by using tegraromgui and loading payloads like hekate. i can load and attempt to boot up atmoshpere but it fails and says power off and then loops back into loading atmosphere over and over. i believe that if i were to use a larger sdcard, i could possibly use emuemmc but i am unsure if i can do that without having a proper dump.

when i try to do anything that accesses the emmc i get the emmc init failed errors. but i was able to get a prod.keys file that looks complete and legit, and i was able to get a dev.keys and the bis keys (i think are for emmc decryption). in tegraromgui, i can mount the sdcard and read/write to it fine, but boot0/boot1 or raw just hangs and never mounts in explorer. my question is that i am fairly certain the emmc has failed. is there any way i can say for certain that it is indeed the emmc? since it boots in rcm mode and loads payloads, it looks like the memory and apu and all are working fine, but i know that a little short here or a little short there will cause certain things to not work right. is there a detail schematic that a person can get that shows correct values? i have a little experience in soldering and a shit ton in programming. i wrote from scratch a ps3 flash tool that would extract and decrypt and validate ros0 and ros1 and many other sections of ps3 flash, i helped a bit with famous bwe flash tools for ps3... but i would really like to try and get this switch back working.

and the question, after all of that typing (phew). if i were to buy another emmc, can i rebuild new emmc data and write it to a new chip? i see some posts where people claim to have used their per console keys to rebuild the emmc flash data? is this possible? is there a switch developer wiki like ps3devwiki? something that woudl explain all of this?

any info is greatly appreciated and i am dedicated to getting this thing back working. just would like to know if there is any posts with dedicated schematics with expected values, and if i can swap emmc and rebuild and flash it and get it back going.

i have 14/64 fuses burntsku is 83, i didnt even think to look at what firmware it listed, but i will see if i can find that tomorrow. but any information is appreciated! thanks for reading

p.s. if i need to make anything more clear please just let me know.

 

[james28909]

well i think i might have found the problem. looks like there is a ton of at the bottom side of the console near the vents for the fan. the headphone jack/game card reader is covered in corrosion and there is corrosion on a few spots on the back side of the motherboard. i will take a few pics. this thing is easy af to disassemble lol. i also think the connection for the wire that connects to the wifi board is corroded, so i will probably try to clean that up as well. i am pretty sure this is why it enters rcm mode, and since its in rcm mode tegra rcmgui is able to send payloads.

one other thing i noticed this morning is that the battery seems to be draining pretty fast, and it is a new battery.

question is, what do i clean it all with? +90% alcohol? is there anything better than that? thanks for any information

 

[The Real Jdbye]

well i think i might have found the problem. looks like there is a ton of at the bottom side of the console near the vents for the fan. the headphone jack/game card reader is covered in corrosion and there is corrosion on a few spots on the back side of the motherboard. i will take a few pics. this thing is easy af to disassemble lol. i also think the connection for the wire that connects to the wifi board is corroded, so i will probably try to clean that up as well. i am pretty sure this is why it enters rcm mode, and since its in rcm mode tegra rcmgui is able to send payloads.

one other thing i noticed this morning is that the battery seems to be draining pretty fast, and it is a new battery.

question is, what do i clean it all with? +90% alcohol? is there anything better than that? thanks for any information

Vinegar (followed by IPA) might be more effective.

 

[james28909]

Vinegar (followed by IPA) might be more effective.

i was recommended by someone at another forum to use brake parts cleaner in a can. that shit will clean grease off of aluminum and they also make an electronic safe version. like safe for sensors and plastic so i wonder if that would work?

one other question, with the motherboard completely removed, and nothing hooked up to it... if i attach the usb will it go into rcm mode automatically? because if not then i have a short or problem somewhere i cannot find ;l but if it is expected behaviour then i will finish cleaning and reassemble. but if the emmc is not detected or toast or corrupt, then it will go straight to rcm mode when a usb is attached? also, thanks for the idea about vinegar, didnt even think about that tbh

 

[l7777]

Corrosion is like tooth decay, you can't just clean it off with a spray or solution, you'll need to remove the components and replace the corroded solder on the components and pads or it will come back. If the pads or component leads have corrosion then you'll want to replace the components and jumper around the affected pads.

 

[james28909]

Corrosion is like tooth decay, you can't just clean it off with a spray or solution, you'll need to remove the components and replace the corroded solder on the components and pads or it will come back. If the pads or component leads have corrosion then you'll want to replace the components and jumper around the affected pads.

so far i only found one spot on the motherboard on the backside. if you hold the motherboard with the usb facing up and look at the back of the motherboard, there is a tab sticking down with a few smd cas and a black ic of some sort. the corrosion was only inbetween this IC and the very small caps that are above it.

edit: actually... i just looked again and i can clearly still see some corrosion up underneath this IC. what does this IC control?

edit2: lol actually this is the charger controller IC isnt it? if there are direct shorts under it then it could be sending extra juice or not sending juice at all to the emmc? is there any kind of detailed explanation of traces and where they go and what they do? surely this ic handles more than just charging, does it handle supplying power to other components on the motherboard as well?

 

[The Real Jdbye]

i was recommended by someone at another forum to use brake parts cleaner in a can. that shit will clean grease off of aluminum and they also make an electronic safe version. like safe for sensors and plastic so i wonder if that would work?

one other question, with the motherboard completely removed, and nothing hooked up to it... if i attach the usb will it go into rcm mode automatically? because if not then i have a short or problem somewhere i cannot find ;l but if it is expected behaviour then i will finish cleaning and reassemble. but if the emmc is not detected or toast or corrupt, then it will go straight to rcm mode when a usb is attached? also, thanks for the idea about vinegar, didnt even think about that tbh

If the NAND module is not connected, it will boot into RCM. I think it should boot normally with just the motherboard + NAND module but don't quote me on that. It certainly doesn't need the screen or backlight connected, I do know that much, as Switches with damaged screen connectors that can still be used docked.

 

[james28909]

ok. well after cleaning i am still getting the emmc init failed on anything. at this point i am about positive the emmc has failed. i have found some posts about using a sdcard and adapting the emmc board to it to hook up to a computer so i will try that out tomorrow and see what happens. as cheap as the emmcs are, i might just buy one from ebay or amazon. do you know of a reliable and trust worthy place to buy them? does anyone in the scene deal in parts or anything? anyone local to this forum maybe?