(WIN7) Arduino Uno not reconized on computer

Greetings,
I am trying to connect my arduino Uno to my PC (windows 7) and it wont seems to connect.
I dont hear the windows connect sound.

I have already updated all USB bus controllers in my device manager and nothing
I tried two cables that I know works
I plugged my 3D printer to my computer with the same cable and it shows up in my device manager
I reset my BIOS

when I plug my Uno in, the ON light and L light both light up.

Is there a way to tell if my Uno is fried or broken? or something on the computer end?

I bought this Uno about 3-4years ago and havent used it since.

You should NOT need to reset your computers BIOS for an Arduino.

Few quick questions.

What type of USB ports are you using as some implementations of USB 3.0 don't play nice with Arduinos.

There have been one or two reports of corrupt boot-loaders over longer periods of time (hard to see how) so maybe it needs a new boot loader.

Do you see nothing in the device manager at all that might be the UNO eg exclamation or question marks ?

Which version of the IDE are you using ?

Can you identify the smaller chip near the USB port on the board or supply a picture ?

Also, did the board ever work before?

Not bootloader issue - it's an Uno or clone, and it's not showing up on USB, so it's gotta be a problem with the serial interface chip. It could be the firmware on the 16u2, but this very unusual. Could also be bad hardware, or the issue noted above with USB 3.0 ports.

Ballscrewbob:
You should NOT need to reset your computers BIOS for an Arduino.

Few quick questions.

What type of USB ports are you using as some implementations of USB 3.0 don't play nice with Arduinos.

There have been one or two reports of corrupt boot-loaders over longer periods of time (hard to see how) so maybe it needs a new boot loader.

Do you see nothing in the device manager at all that might be the UNO eg exclamation or question marks ?

Which version of the IDE are you using ?

Can you identify the smaller chip near the USB port on the board or supply a picture ?

Im using a USB 2.0. I dont see anything in the device manager at all. No exclamation or question marks, I tried to scan for changes but still nothing, not even the sound it makes when plugging something into the computer.
Im using 1.6.12 i believe is the latest one.
If Im looking at the right chip it says 501v but ill upload a pic also

DrAzzy:
Also, did the board ever work before?

Not bootloader issue - it’s an Uno or clone, and it’s not showing up on USB, so it’s gotta be a problem with the serial interface chip. It could be the firmware on the 16u2, but this very unusual. Could also be bad hardware, or the issue noted above with USB 3.0 ports.

Yes I worked about 3-4 years ago. I tested some servos, thats all. then jsut been sitting in the box, in my drawer.

The chip I was telling you to look at is the black square - it's a 16u2 (or 8u2, if it's that old) (indicating official board or faithful clone). Unfortunately those seem a little easier to damage than the CH340G's used on the bargain basement clones (either that, or they're so cheap people don't bother posting about it when they fail)

One thing that stands out to me is that there's a header on the 16u2's ISP port, which I don't think they normally populate (they have the holes, but nothing in them). Was that something you might have installed in order to load different firmware onto the 16u2 in the past, or was it like that from factory? (check the solder job on the header if you're not sure - if you added the header, you probably used it)

I'd try putting an ISP programmer on it and seeing if I could talk to the 16u2 with that, and if I could, try to reload the firmware on it.

@ DrAzzy my "real" UNO also has the headers pretty sure they are R3 as I have one here with the headers and yes its a true UNO.

@ takadakeyo

Long shot but carefully remove the chip (remember the orientation) and then re-insert it all the way carefully and firmly.

DrAzzy suggestion is a great one if you have something to hook up the the ICSP headers to see if you can talk to it.

DrAzzy:
The chip I was telling you to look at is the black square - it's a 16u2 (or 8u2, if it's that old) (indicating official board or faithful clone). Unfortunately those seem a little easier to damage than the CH340G's used on the bargain basement clones (either that, or they're so cheap people don't bother posting about it when they fail)

One thing that stands out to me is that there's a header on the 16u2's ISP port, which I don't think they normally populate (they have the holes, but nothing in them). Was that something you might have installed in order to load different firmware onto the 16u2 in the past, or was it like that from factory? (check the solder job on the header if you're not sure - if you added the header, you probably used it)

I'd try putting an ISP programmer on it and seeing if I could talk to the 16u2 with that, and if I could, try to reload the firmware on it.

Yeah I havent done anything to it, it came with it from factory. Is there another way to try reload the firmware?

Its loosely termed “flashing the bootloader”.

A lot depends on what you already have available and there are a plethora of methods.
If that is something you wish to try I suggest a good google first.

All I do is plug into the header select the USB TINY from the programmer list, select the correct board and then hit the burn bootloader option.

I use a cheap USBTINY myself. but also have a better one if I need it (not so far).

Ballscrewbob:
Its loosely termed "flashing the bootloader".

A lot depends on what you already have available and there are a plethora of methods.
If that is something you wish to try I suggest a good google first.

All I do is plug into the header select the USB TINY from the programmer list, select the correct board and then hit the burn bootloader option.

I use a cheap USBTINY myself. but also have a better one if I need it (not so far).

Im trying this method

But when it says "link" them, Im guessing it means connect them. I do that but get stuck on step #5 because after I unconnected the two pins, the Uno is still not recognized.

I tried to uninstall arduino and reinstall with my uno plugged in and i get the port/coms in my decive manager that says arduino uno com5 with an exclamation mark, when I try to update driver i get the error code 10, and my arduino program doesnt recognize it under ports.

now the weird part is when i unplug my uno the “arduino uno com5” stays. I change usb and nothing happens. I remove the com5 from my device manager list and plug my uno back and sure enough, nothing happens, not recognized and doesnt show up on my computer anymore.

In all honesty I think you might also have other issues too by the sounds of it.

Arduino have thier own method HERE for updating the 8u2. complete with pics.