Can this keyboard can be fixed?

[huog]

TLDR: I flashed my keyboard with the wrong file, now it doesnt work. Main suspicion is that I crapped the bootloader, now I’m wondering if I can change the controller on it. Can I just ATmega 32u4 and solder it? or Is it more complex than that.

Warning: Lots of yapping

Hello its my first post, I been waching level1 for like 2 years, but I just decided to come here with a problem hehe. I have this custom keyboard that I bought in 2021 and worked and sounded very good. But it started giving me problems last month. Some keys when pressed would not do anything, but if I kept pressing, it would start working. I tried cleaning it and switching switches from places but the keys still were weird, as the faulty ones changed over time(not with the movement of the switches).

So a few days ago I said “damn it” and I tried to flash it again, as I tought it was maybe a buggy firmware, so I went to the folder where I had saved the file .bin, but I made a mistake and chose a .json file with same name (used for a program called via). I only realized what happened because my keyboard was dead.

All the troubleshooting was worthless, and Kimi arrived at the conclusion that it was the bootloader and said that the default one if prone to failing. I went to the discord of the company that made it and they said the pcb was dead. But I wanted to repair it so I tried to reflash the bootloader with the help of AI.

I tried doing this with some chinese little clips for ics, but my ic was too small and I had to find where the pins requiered for ISP. I didnt solder a wire to the keyboard because I don’t have my soldering iron at my dorm. The process failed, but it may be due to bad conection with the little clips.
dead

avrdude -c arduino -P /dev/ttyUSB0 -p atmega32u4 -b 19200
Device signature = FF FF FF (retrying)
Device signature = FF FF FF (retrying)
Device signature = FF FF FF
Error: invalid device signature
Error: expected signature for ATmega32U4 is 1E 95 87

double check connections and try again, or use -F to carry on regardless

I have to be honest and say that I’m out ot my level here, the problem right now is the bootloader. But in my investigation I discovered that the original problem may be broken copper traces as is one of those keyboard that have some flex. I have spent around 25usd in this, I know it isnt much, but is half the price of a new pcb and half the price of a decent keyboard. I decided to try to fix it only because a local shop had the clips in stock and I tought that this would be fixed in max two hours.

So the conclusion: Should I try to solder the cables to try to flash it? Can I buy a new ATmega32u4 and replace the original? ( I have friends with the ability to solder it). If anyone has a recommendation of what can I try, it would be so helpfull.

[Laikulo]

Getting back all 0xFF in the signature means it’s probably not properly connecting. Any time you see a bunch of FFs, it usually means something isn’t connected correctly, or is blank.

A few things that jump out to me:
avrdude -c arduino is for programming the Arduino itself. You probably want avrdude -c arduino_as_isp . Do avrdude ‘-c?' for a list.

If you did a force with -c arduino, you may need to reflash the arduisp from the arduino IDE.

The idea is to turn the arduino into a programmer (aka ISP), and then use that to flash the actual target (the keyboard)

Depending on which version of the arduisp firmware you flashed to the ardiuno, you may need to use the pins on the ISCP header to connect to the target. It’s not very well documented. When you load the example program (arduisp) into the IDE, there are comments at the top which state which pins should go where.

[Laikulo]

For completeness, here is the comments I see with the bundled version of ArduISP in the verison of the Arduino IDE that I have

// This sketch turns the Arduino into a AVRISP using the following Arduino pins:
//
// Pin 10 is used to reset the target microcontroller.
//
// By default, the hardware SPI pins MISO, MOSI and SCK are used to communicate
// with the target. On all Arduinos, these pins can be found
// on the ICSP/SPI header:
//
//               MISO °. . 5V (!) Avoid this pin on Due, Zero...
//               SCK   . . MOSI
//                     . . GND
//
// On some Arduinos (Uno,...), pins MOSI, MISO and SCK are the same pins as
// digital pin 11, 12 and 13, respectively. That is why many tutorials instruct
// you to hook up the target to these pins. If you find this wiring more
// practical, have a define USE_OLD_STYLE_WIRING. This will work even when not
// using an Uno. (On an Uno this is not needed).