precision 690 USB header pinout - install a 4 pin internal card reader/floppy

I went trough this some time back on my Precision 380. It is a bit of struggle as Dell Flexbay does not have a standard pin out as you found out. You will also find that the four wire terminal does not match the pin spacing and will likely not fit as you showing it in your photo (unless this was changed on 690, but somehow I believe not). I finally got it done with modified Dell ribbon cable.

Have a look at this post. You will find it enlightening.

http://www.dellcommunity.com/supportforums/board/message?board.id=dim_other&thread.id=224098&view=by_threading&page=1

Ratz

Thanks a lot RATZ for all this information... but alas it is not the same situation on my DELL 690:

here's a photo of my USB header, 

 http://patatronic.com/question.jpg

as you can see there are only 6 pins ...!

Plus the 4 pins plug fit - has the same spacing - I just have no clue about the pinout...

this header is quite different - anf the thread you sent is about this pinout...

http://tekmandan.tripod.com/id1.html

I was just wondering if somebody had the same problem... ?

or if somebody could tell me if solution 1 or 2 represented on my photo could work ... ?

thanks a lot for any help or input!

Did you actually tried to fit the four pin terminal onto the USB header pins???? The reason I am asking id that spaces between the pins is not standard as well according to this sentence.

"This header is unique in the way that is has 2 MM pin centers instead of the conventional 2.56 MM or .1 inch pin centers that a normal USB header would. No standard connector will fit this header. The only connector I have found to fit this header is Digikey part# WM14310-ND".

You could verify if this statement applies is to plug it in while the PC is turned off. Maybe Dell changed the pin spacing to the standard .1 of an inch on your motherboard. Even if Dell did that and you are able to plug it in your dilemma still persist as the pin out may not be in the same sequence as your four pin plug of your USB device.

To determine that you may try what I did and check the pins on the header of your motherboard with Voltmeter. At least you will be able to find 5Volts positive and negative and then determine which is D+ and D-.

It took me long time before I had the courage to plug it all in as I was afraid of the damage to the MOBO, but I was lucky. Here is a link to another useful website.

http://www.directron.com/installusb.html

Added. This link above is what gave me the courage to experiment as the statement  #1 in Troubleshooting indicates that as long as you do not mix up 5 Volts positive and negative there will be no damage. if you mix D+ and D- then the part will not function but no damage is done. As I said it is easy to figure out which is 5Vot positive and 5Volts negative so you should not run into burning anything. At least that is how I read it.

Hope this helps.

Ratz

Thanks a lot!

very useful information 

I will figure out where the +5v and -5V are and then make a few tries...

...

also I managed to plug my 4 pins plug into the MOBO heather...

spacing really felt the same...

I will have double check when I am at home.

thanks again for your precious help!

luc 

You are welcome.

Glad to hear that spacing of the pins is the same. At least that is an improvement over the earlier connectors.

Good luck, and please let everyone in here know when you discover the polarity of the pins of the motherboard.

Ratz

I made it work finally ...

and I discovered that on my mobo (precision 690) I have 2 USB header: one that is located close to the power button - on the front - and the second one :

http://patatronic.com/question.jpg

that is on the MOBO close to the satat plugs etc ...

So on my photo I have 2 ways of plugging the card reader: none of those actually works:

the right solution is solution #1, but the other way round.

= the +5v pin is the bottom right pin (again, on my photo - link attached)

...

I just checked with my volt meter to see where the +5 pin is, and I plugged it knowing - thanks to your information - that I only risk that it won't work ...

But it does !

Under xp 32 bit and x64 pro ...!

so thanks a lot for your help, Ratz

luc 

That is a good news. I am glad it all worked out for you.

Thanks for coming back to the forum and posting the results.

Ratz