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Testing Arduino Compatibles
As of May 12, 2016 dipmicro tests all Arduino UNO, Nano, Mega compatibles due to issues with deliveries from China. The common issues were obsolete or missing bootloader or sometimes even faulty USB connection. I also seen bad soldering job on USB 12MHz crystal causing USB to fail.

This was an emergency procedure I implemented under time stress to rule out most common issues. It will not test all aspects of CPU, but it makes sure unit has working CPU with bootloader, working USB and can be uploaded over USB from Arduino IDE.

Here is the procedure, I would like your feedback. It may also help people troubleshoot their Arduino and compatible. My experience says if tested board does not register with Arduino IDE, it is not installed or bad serial port driver.


Windows 7 PC with Arduino IDE
USBASP with 6-pin ICSP connection


1. Plug Arduino or compatible unit into USB port
2. If serial port requires to be installed, wait for installation
3. Open Device Manager and identify COM port number by plugging/unplugging
4. When unplugging first and plugging second unit, the COM port number remains the same
5. Load sketch Blink10Hz into Arduino IDE, select correct board and port

Unit Test

1. USB: plug Arduino to USB port, observe sound as PC recognizes it. Any hesitation of the sound, put aside.
2. Bootloader: observe LED flashing several times by bootloader
3. Upload: Upload Blink10Hz sketch and observe Done Uploading in the status area
4. Observe LED flashing at frequency 10Hz

Common Issues

USB not working

May be bad/missing 12MHz crystal, bad/missing/reversed CH340 chipset, bad USB connector, etc. If cannot fix, return to vendor or discard.

Missing Bootloader

Select Tools -> Programmer = USBASP 
Attach USBASP to 6-pin ICSP connector
Tools -> Burn Bootloader
Interesting, I noticed the faster flashing on some of the ones you sold us. Had one today from that batch that showed up on usb but would not accept flash so I initially thought the faster flashing was some hardware defect but then I tried another and it was fine. Did not really investigate further since the rest I tried worked.
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If things weren't meant to be modified, they would not come with wires attached.
Jon, the ones I sold to Avid recently were not all flashed, about 40% had missing bootloader and it was programmed by Arduino IDE 1.6.3. The ones that came with bootloader were only tested, not reprogrammed.

So I am curious if ones that flash faster are factory programmed or 1.6.3 programmed.

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