Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

got only this one. I'll look at home later, maybe I've got more. need them, too. I'm heading for a new trial :)

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

Just remember, that one thing was marked wrongly on this photo - ID pin shouldn't be soldered together with ground. It will work, but You'll loose possibility of detecting ID pin state with *may* be used in future by some package, H-E-N for example.

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

anyone still got the picture of the golden pads under the battery? of course with description.

edit: ah it's back online :)

http://talk.maemo.org/showthread.php...818#post997818


edit2: I've made a diagram for myself, to see how I have to connect my socket. the pink lines will be my wires from the usb socket to the pads. maybe it's useful for someone else:

edit3: Today I've soldered it like on the picture. Problem is not solved, but now, if I plug in the device on a computer or on the charger, it shows up the USB-symbol and asks for the connection mode (mass storage or PC suite).
I think I've made something wrong with the GND connection, because it came to my mind later, someone mentioned here, that GND is not USB-GND!

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

See my post:
http://talk.maemo.org/showpost.php?p...7&postcount=13

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

doesn't matter.
usb data lines are LVD* type so GND noise is rejected.
but BGND** != GND because between is placed a resistor for current sensing, used by BQ27200 chip

* LVD low voltage differential
** BGND battery ground

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

I have a different issue with the usb port and wanted to see if you guys could help..

One of the chip is gone from the board near the usb.. and I don't know what it is and the value of it.

Could someone give me that info and maybe even tell me where to get a new chip

See photo

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

So.. it is not a resistor afterall but a SMD ceramic capacitor.. On the schematic it is F5300 marked with a value of 2.0A, but what is that mean? What SMD capacitor I needed?

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

I personally would have guessed it to be a diode, but your schematic is showing it as a capacitor? 2.0A makes sense for a diode, being the amperage it can handle at 5v before it blows. A capacitor would be listed in Farads (or micro/pico Farads in this case).

Are you sure it's not a diode? Diode would make a lot more sense given it's location.

An example replacement would be something like this. That one comes in 8 or 12mm (though I'm sure you can find something similar in the proper packaging/spacing with minor searching on other sites).

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

Hey Woody, thanks for the reply

I don't know... I was reading that it maybe a ceramic capacitor, but I am not really sure..

The symbol on the schematic don't make sense.. I have attached the part of the schematic I am looking at...

It is the one circle (squared) in red.. it said F5300 (the position code on the board) and 2.0A...

http://catsitting.com/temp/1.jpg

Re: Soldering advice needed for re-attaching N900 USB to mainboard.
 

It doesn't really make sense. A capacitor would look like the others in the diagram (C5301, for example), but you'd think it if were a diode it would look like the one shown near it (N5300). Are you sure these are position codes? It seems awfully convenient that all the things labeled with a C are capacitors... I'm thinking it may be more a part reference list.

In any case, the only thing I can think of that would list amperage would be a diode. Capacitors would be in Farads (27pico, 100nano?). If these aren't location codes, maybe the F stands for fuse? Do they make ceramic SMT fuses?

Turns out they do. Here's a 2.0A at 24V. Just find a 2.0A at 5V and I'll be that's your candidate. That could also explain it "evacuating" the board when overloaded?