Picofly (RP2040) OLED getting error Failed to init eMMC. But with HWFLY working fine.

[Maq47]

hi!, I have the solution!, same problem, I solved it by adding 4 resistors, yes, 4! on dat0, on a rp2040-tiny (and one more on cmd but I don't think it makes any difference). In fact, 235 ohms at dat0 (4 added + 1 on board), It only happened to me once with an emmc sk hynix.

Post automatically merged: Sep 29, 2023

The difference is the value of the resistor that comes in dat0.

GG! You deserve a tip for your generous work. Ever considered getting a Ko-Fi? I'm sure someone will tip you for this.

 

[linuxares]

hi!, I have the solution!, same problem, I solved it by adding 4 resistors, yes, 4! on dat0, on a rp2040-tiny (and one more on cmd but I don't think it makes any difference). In fact, 235 ohms at dat0 (4 added + 1 on board), It only happened to me once with an emmc sk hynix.

Post automatically merged: Sep 29, 2023

The difference is the value of the resistor that comes in dat0.

Would a 1880 Resistor work as well then?

 

[VenCraft]

Entonces, ¿funcionaría también una resistencia de 1880?

Exactly, it should work, but I only had 47 ohm resistors and I couldn't put one with a higher value to make it neater.

 

[PaulGr]

I have the same issue with purple screen after installing picofly from Ali, and I understand that installing HWFLY solves the issue somehow, the problem is there are only INSTINCT clones are for sale now. Do they also solve the issue? Anyone had experience with it?

 

[Maq47]

hi!, I have the solution!, same problem, I solved it by adding 4 resistors, yes, 4! on dat0, on a rp2040-tiny (and one more on cmd but I don't think it makes any difference). In fact, 235 ohms at dat0 (4 added + 1 on board), It only happened to me once with an emmc sk hynix.

@PaulGr This is the solution, literally at the bottom of the previous page. You should read the thread next time.

 

[PaulGr]

@PaulGr This is the solution, literally at the bottom of the previous page. You should read the thread next time.

I read the thread and saw this solution, but this is not what I asked. I asked about other solution with installing HWFLY.

 

[Hayato213]

I read the thread and saw this solution, but this is not what I asked. I asked about other solution with installing HWFLY.

I know that people swapped RP2040 with regular Hwfly and the purple screen went away, but v4/5 chip are so rare these day.

 

[Maq47]

I read the thread and saw this solution, but this is not what I asked. I asked about other solution with installing HWFLY.

Ahhh, you want to fix a purple screen before trying the solution. I'm a little slow this morning, woke up an hour ago. Well, you could always try the Trading Area forum to try to acquire a HWfly from a member here. Other than that, there's eBay. Those are your best bets.

 

[PaulGr]

The problem is I can't really "try" the solution with adding resistors. The picofly 2040 board I have already has 240 ohm resistor on DAT0.. guess I'm out of luck here.

 

[Maq47]

The problem is I can't really "try" the solution with adding resistors. The picofly 2040 board I have already has 240 ohm resistor on DAT0.. guess I'm out of luck here.

View attachment 413451

So you tested these values yourself with a multimeter? If so, then PicoFly must have put out a revision with a better resistor on board, but if you're saying that this results in a purple screen as well, then maybe that post wasn't the only solution, but a possible solution? To be sure, you are putting this in an OLED, correct? This issue only happens on an OLED with PicoFly 2040 for OLED installed. If this model is not designed for an OLED unit, or you are trying to install it in a Switch Lite, then that 238 ohm resistor will indeed cause a purple screen.

 

[PaulGr]

Yep, I tested the resistors with a multimeter and yes, that's an OLED model.
I've already modded 2 oled's with similar picofly boards and all worked fine. Now, the only thing that comes to mind is that those 2 oled's were 16.+ FW. And this one is 17.0.1

 

[Maq47]

Yep, I tested the resistors with a multimeter and yes, that's an OLED model.
I've already modded 2 oled's with similar picofly boards and all worked fine. Now, the only thing that comes to mind is that those 2 oled's were 16.+ FW. And this one is 17.0.1

Uhhhh, yeah, that'll probably do it if AMS isn't the latest version and you don't disable blanking the serial in ProdInfo.

 

[VenCraft]

Yep, I tested the resistors with a multimeter and yes, that's an OLED model.
I've already modded 2 oled's with similar picofly boards and all worked fine. Now, the only thing that comes to mind is that those 2 oled's were 16.+ FW. And this one is 17.0.1

Hi!, Rarely, but it happens, some models are not compatible with aliexpress chips. In all cases I solved it with rp2040-tiny and extra resistors in dat0 and sometimes also in cmd. Anyway, I don't remember getting a purple screen, I do remember partitions being deleted or a slow emmc.

 

[PaulGr]

Ok, so the purple screen issue is solved!
Had to add 100 ohm resistor to DAT0, on top of the existing 240 ohm (total 340 ohm) and it worked perfect. Booting to OFW and CFW no problem.

 

[Hassal]

Ok, so the purple screen issue is solved!
Had to add 100 ohm resistor to DAT0, on top of the existing 240 ohm (total 340 ohm) and it worked perfect. Booting to OFW and CFW no problem.

You might be on to something. Normally when people get this purple screen it means their user partition table vanished and the only way to retrieve it was using HWFLY.

Can't really say for sure but it seems like you found a solution to this "bricking" issue that people been facing forever.

 

[PaulGr]

You might be on to something. Normally when people get this purple screen it means their user partition table vanished and the only way to retrieve it was using HWFLY.

Can't really say for sure but it seems like you found a solution to this "bricking" issue that people been facing forever.

Not sure if this is a solution for a vanished user partition table, but definitely a solution for this kind of purple screen.
My eMMC didn't init in hekate, I got "emmc init failure" error, while to see vanished user partition table, eMMC must at least pass init stage.

Btw, I modded 2 more oled's after that with the same picofly board, one was samsung eMMC and the other one hynix. Both worked fine. So yea, no clue what had happened, can't see any pattern.

 

[Hassal]

Not sure if this is a solution for a vanished user partition table, but definitely a solution for this kind of purple screen.
My eMMC didn't init in hekate, I got "emmc init failure" error, while to see vanished user partition table, eMMC must at least pass init stage.

Btw, I modded 2 more oled's after that with the same picofly board, one was samsung eMMC and the other one hynix. Both worked fine. So yea, no clue what had happened, can't see any pattern.

If you want to help provide input to help others you could reproduce the problem (of course after doing backup and stuff).
This time you need to check your NAND table. I personally only seen this happen one time after modding hundreds of units.

According to this purple screen can mean several things one of course related to GPT table.

 

[etnicor]

Question, where do you place the extra resistor for dat0?
Just somewhere inline from dat0?

Replacing the 238 ohm resistor even with microscope seems pretty tough.