ESP32 Forum

Posted: **Mon Apr 19, 2021 9:36 am**

Hi all,

I have a lot of ESP32s due to the courses I give at a University of Applied Sciences. However, 4 of them behave rather bad. They do accept upload, but then enter a boot loop with this output:

Code: Select all

rst:0x3 (SW_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0018,len:4
load:0x3fff001c,len:1216
ho 0 tail 12 room 4
load:0x40078000,len:10944
load:0x40080400,len:6388
entry 0x400806b4
ets Jun  8 2016 00:22:57

What I would love to know is, can this be fixed, and if yes, how?

I have found many sites where people issue instrustions on this but none so that I could actually understand how to do it.

All information much appreciated - thank you!

Posted: **Mon Apr 19, 2021 5:53 pm**

Are they all the same hardware and same binary? What is a log from a working device? What sdk version was used?

Posted: **Mon Apr 19, 2021 6:13 pm**

Yes, they are all DevKitC chips, but they have functioned perfectly well in both Arduino and MicroPython settings. I just started to test my stock, and found these four that fail.

So, all in all, is there a way to get them going again?

Posted: **Mon Apr 19, 2021 10:51 pm**

If you are erasing the flash and reflashing a new bootloader and app and they don't work while other identical units do work then I have no suggestions.

Posted: **Tue Apr 20, 2021 4:40 am**

That's what I was afraid of. Oh well, they served well, but my students probably fiddled with the wirings while it was connected.

Or maybe I did.

Thank you for confirming that they cannot be resurrected.

Posted: **Mon Jan 22, 2024 10:31 am**

I have found the same boot loop issue. I know I did
something wrong to get in this state but

You said you had four that were bricked.

Can you say out of how many you have for your labs total?

Posted: **Tue Jan 23, 2024 6:47 am**

Probably 50.

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