Hacking Hardware Picofly eMMC test failure - read failed

[Karichi1919]

Brand new modchip installation, I'm getting =*== eMMC test failure - read failed. It's an OLED switch, boots fine in OFW.

I used the alternative Dat0 soldering point by grinding through the layers. I know I didn't damage anything because as I said it works well in OFW.
To debug it I've individually desoldered each wire until the error didn't change. Found out that turning the console on without the CPU wire also yielded =*== eMMC test failure - read failed

So then I've tried:

• Testing my CPU adapter with a bench power supply, found that it works
• Redoing the CPU caps soldering, it was already well done
• Redoing the soldering at the modchip side, same issue
• Using 94 Ohm resistors on CMD and DAT0, same issue
• Using another known working modchip, same issue
• Measuring diode readings, they're all within 0.5-0.7V and RST is 1.7V

Any advice? Thank you.

 

[jkyoho]

upload the alter dat0 point you grind

 

[Karichi1919]

upload the alter dat0 point you grind

It's sort of covered in hardened UV mask so I don't think it's a good idea for me to dig that all out. You'll have to trust me that it tests well in diode mode, and if I desolder the dat0 wire it changes to =* D0 is not connected

What did you have in mind? Think I might have soldered to the wrong point?

 

[jkyoho]

It's sort of covered in hardened UV mask so I don't think it's a good idea for me to dig that all out. You'll have to trust me that it tests well in diode mode, and if I desolder the dat0 wire it changes to =* D0 is not connected

What did you have in mind? Think I might have soldered to the wrong point?

That is only thing I could image

 

[Karichi1919]

That is only thing I could image

In all fairness you're starting to make me doubt myself here, got any advice for dissolving/softening the UV mask so I don't have to pick it out? I assume picking at it is likely to tear off the internal layer.

 

[jkyoho]

In all fairness you're starting to make me doubt myself here, got any advice for dissolving/softening the UV mask so I don't have to pick it out? I assume picking at it is likely to tear off the internal layer.

Not really I believe, The uv risen mask I use dont tear anything off If I hot air them and lift them up.

Give a try on some random empty area dry a dip of the uv glue and pull it up

 

[Karichi1919]

Not really I believe, The uv risen mask I use dont tear anything off If I hot air them and lift them up

Right, hopefully that'll work. My resin gets REALLY tough and it sticks down very well since I use a UV curing lamp made for this purpose.

Post automatically merged: Nov 19, 2023

Not really I believe, The uv risen mask I use dont tear anything off If I hot air them and lift them up.

Give a try on some random empty area dry a dip of the uv glue and pull it up

You're right, I used the wrong point. Idk what that even was. I had to repair the trace since it ripped as predicted, and the switch still works.

I don't think I'll grind again, I don't want to risk damaging my repair. I'll lift and reball the emmc.

 

[zamastyle]

What alternate dat0 point is this? Im not familiar with it.

 

[Karichi1919]

What alternate dat0 point is this? Im not familiar with it.

https://gbatemp.net/threads/switch-oled-alternate-c-point-destructive.623220/#post-10024351

 

[zamastyle]

Holy shit thats a ballsy choice. I dont think I would ever do this on a clients switch but guess who is about to get destructive on their own oled.

 

[Karichi1919]

Holy shit thats a ballsy choice. I dont think I would ever do this on a clients switch but guess who is about to get destructive on their own oled.

hahaha