DEAD UNO!

I recently purchased Arduino UNO on eBay. When I plugged it in it did not work.

I tried three computers all with the same result. The Device Manager shows it as an "UNKNOWN" USB device.

I have an AVR ISP programmer so I reloaded the USB UART firmware. The programmer was happy with it. The code loaded and verified.

I don't know where to go from here. I don't want to waste money on another board that does not work.

Bob Macklin
Seattle, Wa

Sounds like you got an unprogrammed card. It happens. I bought a Lilypad protosnap from Sparkfun. Could not load code into it. Tried every trick I know. Sure appeared to not have a bootloader, no matter what I did it just ran its sketch. SPI pins not broken out either. Chased them several times, they finally sent another with a bootloader. To use the first board without removing the chip, I ended up going to Hobbyking and got an ISP to SMD adapter that you press down on top of the TQFP package to access the SPI pins, and got it bootloaded that way. Adapter cost almost as much as the card.

So, you have some options:
Don't buy from e-bay. I generally don't.

Make your own. I do this a lot. I also make stuff that looks interesting and sell it. Cross Roads Electronics

Buy from a known source. When I do buy, I go this route. Especially ICs. Cuts down on chances of getting counterfeits. And don't need to wait 3-4 weeks for stuff to arrive from China. And a lot of times parts from Mouser/Digikey/Newark are less costly too.

I connected my AVR ISP programmer to it and programmed it with the USB UART/Bootloaded module that is in the download package.

The programmer found the chip, programmed it and verified.

I ASSUME the USB UART/Bootloader code that is in the download package works?

Bob Macklin
Seattle, Wa.

That's the one the IDE uses, so yes.
I program standalone 328P chips and projects as Unos, they work fine with 16 MHz xtal & 22 pf caps.
Even redid my old Duemilanove as an Uno, to keep things consistent.

Did this board have a 16U2 on it? That was programmed ok for USB/Serial?

The AVR ISP programmer says the USB UART is ATmega16U2.

There are only a couple more things I can check on it. The USB interface could be blown.

This is probably why the board was on eBay. Not a big loss. Not worth putting much more time into.

I'm back to working with AVR Studio and my development boards. I don't have a problem with more complex stuff.

I just wanted to find out what the Arduino stuff was all about.

I have some 32 pin TQFP adapters coming. When I get them I will put a 16U2 on one and set up a USB UART for testing.

I just hope I can solder the pins!

Bob Macklin
Seattle, Wa