one board is recognized, but my second board isn't

Hello,

I have two arduino328s. One board will communicate with the computer, but when i plug the second board in, nothing happens. Is it possible I accidentally fried my board? How would I know? When I plug the broken board into the computer the LED attached to pin 13 is on, but very dim. Does this indicate a problem?

Thanks.

Did you connect anything on the "broken" board?
Did your computer report new device, for PC, playing the sound that indicates you plugged in something?

Initially I was testing the StateChangeDetection sketch, which worked. Then I swapped the LED for base of a TIP102 transistor which was hooked up to a solenoid and rectifier. It didn't work so I put it back with the LED and it didn't work. Then I connected it to my computer with everything disconnected and it wouldn't recognize. It recognizes my second arduino on COM4, but when I plug in the broken one COM4 dissapears and only COM3 is available, but it gives the error of not being able to locate device.

Also, This is a bit weird, but I've connected the TIP102 in series with the solenoid. But even without power to the base, its allowing electricity to flow. The solenoid is a 12-24V SMC pneumatic sol.

Thanks for the help!

What kind of arduino are you talking about? A link maybe (I sense ebay arduinos).
Does the power led still light up on the "broken" board?
Do you have a multimeter to test the voltages on the "broken" board?
Did you plug two boards to the same USB port or not?

vandallas:
Initially I was testing the StateChangeDetection sketch, which worked. Then I swapped the LED for base of a TIP102 transistor which was hooked up to a solenoid and rectifier. It didn't work so I put it back with the LED and it didn't work. Then I connected it to my computer with everything disconnected and it wouldn't recognize. It recognizes my second arduino on COM4, but when I plug in the broken one COM4 dissapears and only COM3 is available, but it gives the error of not being able to locate device.

Also, This is a bit weird, but I've connected the TIP102 in series with the solenoid. But even without power to the base, its allowing electricity to flow. The solenoid is a 12-24V SMC pneumatic sol.

Thanks for the help!

Unfortunately I suspect you had a miswiring and somehow applied 12-24vdc to your arduino board. If so, that would have burned out the USB serial chip and the microcontroller. Probably not practical to try and repair the damage either. Live and learn. One should always be using a accurate schematic drawing of the circuit they are wiring to an arduino and double check all the wiring and proper terminals, etc. Those nasty electrons can be very unforgiving at times. =(

ATmega328 boards,
Yes the power led lights up on the broken board.
I do not have a multimeter right now, I took it to work, but will get it back tomorow.
Yes, after I unplugged the working one, I plugged the broken one in. Should I change ports?

Van

DAMN!

I was following Arduino Playground - HomePage but knowing me I probably did cock it up somehow.

Thanks for the help anyways though,

Does anyone have any thoughts on why the transistor is acting that way? I thought the collector was open to the emitter when there was no base voltage?

My power supply is 12V 800mA, could that damage the board?

My power supply is 12V 800mA, could that damage the board?

There are only two places on an Arduino board where you can safely apply 12vdc, the external power connector (center pin positive) and the Vin pin.

Lefty

Maybe I missed it...

but "ATmega328" is not a board type.

So... what kind of Arduino are you using? (Arduino is a system. ATmega328 is a chip.)

Sounds like you blew the transistor and Arduino.
Did you use a base resistor?

No i didn't use a base resistor.

My transistors are all allowing power to flow through, I'm very confused. I thought NPN transistors stopped current flow?

My board is an Arduino Duemilanove

Always use a resistor of atleast 100 ohms between the Arduino and the base of the transistor.

Yeah, my fault, i'm an idiot for not following the diagram closely enough lol

I assumed the middle pin of the TIP was the base, apparently its the left one. O well, lesson learned.

Here's my work come to fruition.

Thanks for the help everyone!