The story is as follows: I had the first Arduino nano and I used it, fried it, connected it to a PC (Win 10Pro), the power does not come on, I looked for an answer on the forum, at first I did not find it, roughly speaking, I scored on this board and went and bought a new one, also a clone and also on Type-C, I played with a new board and applied 6V to the 3.3V line, and this line stopped working and the Arduino was flashed, when connected, a message appeared about (Failed to recognize the USB device), although the power LED lights up and if power is applied to the 5V line, then everything works, I went to the forum again and found 2 reasons that could solve my problem.
Replace the diode (0.5A 20V MBR0520LT1G)
This is a communication chip between USB and Atmega
I solved the problem of the first Arduino with no power supply, I simply soldered a standard diode (0.6V in a transparent case) in parallel (fixed photo 1) and everything played with other colors, this board started!! And it is stitched!!
The problem of the second Arduino is not solved! And I don’t have time to try option 2 (PS. I’m going to Poland soon, so I don’t know if I’ll be able to experiment with the second Arduino, because I have it in perfect condition, regardless of the problem:) ).(fixed photo 2)
all bets are off once you start doing bad things....
You might still have the impression the device could be working, may be by changing one component, but you have no idea of the ripple effects on all the other components on the board... Some other damages or instability may appear later, board can crash with no reason and you'll spend hours trying to think it's bug in your code etc...
I would just recycle those boards and get a new one...(probably around $1 to $2 from the Far East...)
The whole point is that I need 2 boards, 1 with a diode (working) for the project of a detachable clock, the 2nd board is not working for testing other projects...
My point is that if you damaged the boards or some pins by using the wrong voltage or creating short-circuits or whatever then the boards can't be trusted even if they seem to be working.
First image, pins not soldered. ??
Second image, solder work very clearly needs improvement. I'd say at least 30% of those joints are questionable. Sorry, but it's what I see.
The 3.3V source on the Nano is usually produced internally by the CH340 USB-to-serial interface chip. Nothing short of replacing that chip will correct the problem, although you may be able to remove the CH340 and program the board using an ISP programmer, provided nothing else on the board was damaged.
The first image is not soldered, because I already thought that it was not working and I was missing 2 legs for the module, so I barbarically bit off 1 and soldered the second
The second picture, the soldering work is like this, because this Alliexpress board and the contacts did not want to solder, I cleaned them on both sides and they soldered fine
No. That is a voltage regulator that makes 5V from a higher voltage applied to Vin. 3.3V on the Nano clone that you have is made by the CH340 UART bridge. If you fry that, you don't have 3.3V and the board usually cannot be connected with USB anymore to program it, get Serial output etc.
Always use a liquid/paste flux(NOT acid type, visit your local electronics supplier for ideas), even if you're using a solder with rosin core. It makes a lot of difference.
Ok thank you all very much for solving my problem, does anyone know if there is a clone or original Arduino with a large amount of memory and a small size, I am considering the option of developing this Arduino for my project (smart watch based on RTC DS3231 and Oled 0.96" Y-B )
plug it into USB and upload blink, make sure it works
then solder in the ICSP header
replace the 'old bootloader' with a new one. There's instructions for that on the Arduino website, ask if you need to
upload blink again(change the blink rate). Make sure that works.
put a green sticker somewhere on the board, so you know it's good to go.
now you can add the two 15 pin headers.
Changing the bootloader is optional, but I've had clones from China with both variants, and it's downright confusing if you have to switch back and forth.
I've done this with dozens of Nanos now. When I start a project, I know what I'm starting with.
To buy just 1 of the chip will cost as much as a knockoff board!
At the rate you make careless mistakes, you should see what the price discount is for buying 5 or 10 Nano bundles, because there usually is a significant per-board quantity discount. Learn to shop well and over time you should save a lot. Sell extras if you learn to take more care and you may profit. As it is now, you chase losses.
When you have time, learn to make your own DIY-uinos. very little is actually required, especially without the USB on board, like Arduino Mini and Feather. And still, in bulk the cheap but questionable knockoffs will be cheaper!
Arduino quit making the Mini long ago but copies of that should cost less than clone Nanos! To program those, use an Arduino!
