problem connecting the arduino to the computer

Forum 2005-2010 (read only) Hardware Troubleshooting
1

hi

i bought an arduino mega on robotshop.com

so at first it was working nice, but now it seems the computer doesn't recognise it

i've tried it on at least 5 different computers, it just doesn't find it on USB, and the 2 green leds that usualy light on when it is conected don't turn on, but the red led for power is on

so, when we try to upload any program to the arduino, it just doesn't work, and says we have to see the troubleshooting area on the site. there are even some computers where i can't choose the COM3, well the serial port thing doesn't open anything

any of you have any ideas why it would do this?

(and sorry for my bad english i'm french but i figured out i would get help faster on here, so if you don't understand something just ask )

thanks

2

try a different USB lead, check the connectors for damage dirt?

3

Try a different USB cable.

4

the USB cable isn't the problem, i've tried changing it, it still doesn't work, the power is on, but the computer doesn't recognise it

5

On the computer where it was working, I'm going to assume the Arduino was on COM3.

On the computer where it was working, if the Arduino is NOT connected, is there a COM3? What COM ports are on this computer when the Arduino is NOT connected?

On the computer where it was working, if the Arduino IS connected, is there a COM3? What COM ports are on this computer when the Arduino IS connected?

When you connect the Arduino to the computer, does the computer make the "USB device inserted" sound?

6

well, the computers that i've tested were working before but not anymore,
so there is the COM3 both if it's conected and not conected,
on some computers there is also COM1, but i'm not using it,

and now it doesn't make the usb insert sound when i conect it..

7

and now it doesn't make the usb insert sound when i conect it..

Well to keep the fault finding simple, if a PC doesn't 'declare' a new connection when a Arduino is first plugged into a PC usb connector then:

  1. Either the Arduino board (the FTDI chip to be specific) is dead, or:

  2. The FTDI USB device driver is missing or corrupt on the PC.

Your job is to determine which of the two is the cause. :wink:

Lefty

8

well i don't think the problem comes from the pc, as i've tried it on several different which worked before,

and why would the card receive power but no connection to upload anything to it?

9

well i don't think the problem comes from the pc, as i've tried it on several different which worked before,

That is a reasonable conclusion.

and why would the card receive power but no connection to upload anything to it?

retroleft told you why. The FTDI chip is dead. The purpose of this chip is to provide a USB interface on one side and a TTL interface on the other. That's essentially it. If the FTDI chip is damaged, the board will still receive power and will still function it just won't be able to communicate with the PC.

Search the forum for "loopback test".