reset button not lighting led

I can't upload sketches to my Deicemilla. When connected to my Mac book or PC, the led on pin 13 won't light when the reset button is pushed. An iDuino has the same problem but Stickduino will upload sketches. What could be the problem? I joined the grounds of the Arduino and 20v Wal Wort. Could this have fried the internal fuse? I changed the 168 chip without success.

I joined the grounds of the Arduino and 20v Wal Wort.

What exactly were you using that for? I hope you didn't plug it into the Arduino. The Arduino's MAXIMUM is 20V, and most 20V Wall Warts can get as high as 25V with a low load.

If you JUST connected the grounds, it shouldn't have done anything.. you need to connect the ground to complete a circuit if you're using that power supply for say a motor, or chip, or any other external circuitry.

but if you plugged it into your board.. yeah, there's a good chance you blew the regulator, which in turn probably took out the FTDI chip and such. Did it happen on your "iDuino" after doing the same thing? Or was it just after uploading a sketch sometime?

I put the pos into a motor controller L298 board and the gnd to a breadboard rail and also wired the Arduino board gnd to the same breadboard rail. An LED to the 3.5v and gnd lights. How can I test the regulator and other components on the board? Appreciate your help.

An LED to the 3.5v and gnd lights.

What “3.5v” are you talking about? If you mean the “3.3v” or “3V3” line on the Arduino, I hope you used a resistor. Basically, the 3.3v can only supply 50mA, and if you don’t have enough resistance, LED’s will basically taking as much mA as they can until they burn themselves out… and I’ve had some LED’s that would run as high as 70ma without a resistor(was for testing).

If that’s the case, which sounds plausible but doubtful… that would mean that your FTDI chip was probably ruined. (this is what connects the Arduino to your Computer)

But anyways, on to testing! First, un-plug your Arduino from the Computer. Now open the Arduino program, and check under TOOLS → SERIAL PORT and remember which ports are there. (don’t need to remember, just need to know which is new) Now after you got an idea of which COM ports there are, plug the board in, and let the TOOLS menu go away… so click the area where you type sketches… wait just a few seconds. Now, check the Serial Ports ports again. If you don’t have another board in(should be another com port, which is your Arduino), try closing the program, open it up again, and check again. (just to make sure it loaded right)

If it didn’t show up, try different USB ports. May or may not make a difference. (if you don’t get it to show up, chances are the FTDI chip are ruined like explained above)

Next!
Check the Wall-Wart you used. Make 100% sure it’s NOT AC voltage output. You NEED DC output, and I would never use more than 12v with the Arduino’s regulator.

If you found out you made a mistake, and it’s actually AC output… you might want to put a new order in for an Arduino! :X I believe using AC in any circuit with a DC device will cause damage. (unless protected, OR using the correct components, which we’re not)

If it’s DC, then move on: (checking the regulator)
Now grab your multimeter (hopefully you have one, if not find somebody who does, and knows how to use it).
Plug the AC-to-DC converting Wall-Wart into the Arduino. Now, you want to measure Voltage, put the positive (+ or RED, lol), to the 5v line of the Arduino, and then put the Black to the GROUND of the Arduino. It should measure very close to 5v. (may be like 5.10 or 4.90, which is okay)

If you don’t measure anything out of the 5V, or it’s not even close to 5v (such as the 12v you plugged in) then the regulator probably fried… taking components with it in the process!

Hope this helps and I explained good enough. :smiley:

When the board is tested as you suggested, the new ports do appear but still won't upload a sketch. Your instructions were perfectly clear but I did not adequately describe the setup. The grounds (20v and Arduino) are joined at the breadboard. The 20v pos is going to the + input on the L298 driver board (rated 26v). A meter across these on the breadboard shows 5v. Measuring the voltage without anything connected accept the Wal Wort is still 5v. I appreciate you assistance, particularly how to test the board. Thanks. I ordered the 328 Boardino.