Faulty Uno Compatble

Hi Guys,
I’m new to Arduino and Pi and am working through the Sparkfun tutorials. Having a great time up till the 4th sketch, Circuit 1D: RGB Night-Light. The problem is that only the Red colour would light when running the program. After some troubleshooting I think that there is a fault on the board as Pins 10 and 11 won’t respond to an “analogWrite()” command. Fortunately, I have a second board which responds to the code in the sketch.
To further test the board, I set up a sketch with 4 LEDs to check the output of the pins.
I’m using a Uno
The board in question is a Uno compatible attached to Raspberry Pi both purchased from you a few weeks ago.
As a further test I loaded the Arduino IDE onto my windows laptop and get the same results.
I’ve attached the sketches plus some jpgs to illustrate my issue.
Your’s sincerely
John Jackson

Sketches.zip (1.1 KB)

Hi John,

This seems like a very unusual problem. Can you get any output from those pins? Try digitalWrite(10, HIGH);

Hi John,

Have you used a multimeter on the actual ATmega328 pins to determine if it’s a PCB or MCU issue?

If all else fails, as noted on the page you bought from: we recommend and guarantee that the official Arduino Uno, will work with all Arduino educational resources wherever it is referenced.

Hi Stephen,

Thanks for getting back to me. As per your question I tested pins 8, 9, 10 and 11 using digitalWrite(pinNumber, HIGH);
Pins 8 and 9 lit the LEDs and pins 10 and 11 gave no output.

Hi Graham,

Although I hope to be capable of diagnosing the issue with this board in the not too distant future at this point I’m just getting started in electronics and programming so although I possess a multimeter at this point diagnosing where the error is on this board is beyond my skills. If you’d like to send me instructions I’ll gladly test whatever you like.

I’m not sure how to take your second statement. Does this mean you only supply warranty support for official Arduino units and not for the compatible devices you sell?

Hi John,

Official hardware is almost always electrically tested and put through it’s paces.

You can measure the pins directly on the MCU; they’ll read 5V when high and 0V when low. Google “Arduino uno schematic” if you need a nudge in the right direction finding which pins are which.

Graham when I put a mulitmeter across the MCU I get the following readings. Pin 8 ground.
Pin14 PB0 4v
Pin15 PB1 5v momentarily then 3.56v
Pin16 PB2 1.76v
Pin17 PB3 397mv
Power is from USB from Raspberry Pi 3b

void setup() {
pinMode(11, OUTPUT);
pinMode(10, OUTPUT);
pinMode(9, OUTPUT);
pinMode(8, OUTPUT);
void loop() {
digitalWrite(11, HIGH);
digitalWrite(10, HIGH);
digitalWrite(9, HIGH);
digitalWrite(8, HIGH);