nano 328 no longer connecting to PC. is the board dead?

Nano 328
Windows 7 64bit

I was working on a laser tag project earlier today and all was working well. After coming home from the grocery store when i powered the board back on i was getting some garbage in serial print fields when pressing a button. (1 hour earlier this was working perfectly) After a reset the L led would continuously blink and the board was no longer being recognized by Windows. After unplugging and re plugging the usb cord several times the rx and tx leds stopped responding all together.

Currently when the board is plugged in the pwr led is lit faintly and I'm only getting 1.8v across the 5v pin and gnd.

I'm very new to all of this so I don't really know how to do much.

Do any of the chips get hot?

no, none of the chips get warm at all

Then my first guess would be a loose connection.
Since the power seems not to be dissipated, the only reason the 5V could be low is if there is resistance in line or the supply is bad

Ive had some intermittent connections issues with the micro usb jack. Ive completely pulled the board out of the project board I was working on so there's no way I could have crossed a pin or added resistance.

How can I test for/ correct a loose connection?

I looked at the jack and saw the input wires on the usb jack. The power wire from that is showing 5v. So if the usb jack is definitely getting 5v, but the board output is only 1.8v is something broken on the board?

Where does the 5v drop to 1.8v?

the connection to the board its self gets 5v, as for where it drops exactly i don't really know what to check. the pwr led is only getting 1.7 like all the output pins.

It would be normal for the power light to only get 1.8v since it has a resistor and the LED will pull it down to its break down voltage.
The LED should not be faint :roll_eyes: I am afraid I am confused.

it seems like there's an issue with the FTDI chip.

I hooked up the board to a 9.6v battery on the VIN pin, and everything seems to be working still. however it still will not connect to the pc. Ive tried re-installing the drivers and everything and windows still says there's an error with the device plugged into the usb port.

Is there a second way I can update the board not using the usb? or is there something i can try to get the FTDI chip to work again?

Is there a second way I can update the board not using the usb?

Could be, do you own any other USB arduino (or clone) board? You could also hack one of those cheap USB serial cables.

Lefty

Now that I have the board powered again the RX0 and TX1 pins are both at a constant 5v. Is that usual?

The board shipped with a USB cable, is that what you mean by USB Serial Cable?

when plugging the board into USB ports i get the following error

Windows has stopped this device because it has reported problems. (Code 43)

i have tried 2 different cables and every usb port on my PC

no luck

polishvendetta:
Now that I have the board powered again the RX0 and TX1 pins are both at a constant 5v. Is that usual?

Rx at HIGH is normal when serial data is idle, held high by the FTDI Tx pin. Not sure if arduino Tx is normally HIGH after bootloader is done.

The board shipped with a USB cable, is that what you mean by USB Serial Cable?

No, there are USB serial cables avalible that have a USB serial converter chip built into the cable end and output the proper TTL serial voltage levels used by the arduino board. Here is an example: http://www.sparkfun.com/products/9718