Arduino R3 not recognised

Hardware
1

I think I may have shorted out my Arduino R3, I am unable to download sketches as it is not recognised.

How can I indentify which component is defective?

2

Start by checking the 5V and 3.3V outputs. If they are OK, you can continue.

If the board is not recognised by your PC, the serial-to-usb converter (the chip closest to the USB port) is faulty. On official boards (and some clones), it's the 16U2, on most clones the CH340 and some clones even use other chips.

Note that, depending on what you did exactly (short is a broad term), other components (e.g. the 328P) can be faulty as well.

3

Thanks for the advice.

I've checked the 5V and 3.5V and they are working.

I've noticed that the 5V regulator has a mark on it and wonder if that is what is defective.

4

Post a simple schematic showing how this is powered and what the voltages are?

5

Hi,
The power comes from a laptop via a USB A to C cable. It is no different to the way I usually connect the Uno.

6

Does the L led flash 3 or 4 times when you press reset?

7

The regulator is not powering the Arduino, your USB is. The regulator comes into play when you use Vin.

If you do not have the resources or skill set to repair SMD (Surface Mounded Device) technology I would simply replace it.

8

Yep, it does very quickly.

9

I'm not sure what is needed to repair SMD's but have ordered replacements and hope to be able to unsolder the existing 5V regulator.

10

Yo may need to replace the regulator, but it is not likely to be the cause of failure to down load code. Does the ide recognize the device on a Serial port?

11

You can easily desolder the 5V regulator and see if that solves the problem.

12

The IDE does recognise the device on the USB port, I do not have a serial connector.

The Uno will accept simple sketches like "Blink" but when I download Elegoo sketch lesson 6 (I am a beginner so using Elegoo to learn) only one of the LEDs illuminates. That sketch uses digital pins 12 to 8 but only the LED on pin 10 illuminates.

13

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