Originally Posted by abill_uk

PS and if i am not wrong this mod will bypass the charging circuit and not a wise move at all.

Originally Posted by lorul2

OK I have recently joined the broken USB club ( ) . I understand your point about the circuit protection, however I would like you to answer these 2 questions for me.

1. If I developed a circuit board which had the protection your talking about to use these easily accessible points as my new USB connection. Can you detail the entire circuit from the USB cable back to the test points.

2. If there are "easier ways to fix those pads" please detail how you would do it for someone who may not have access to the proper tools, or the small circuit expertise to attempt such a fix.

[...]

Originally Posted by joerg_rw

The protection is to isolate $random_cable introduced mess from N900, as

Code:

$random-cable -> connector -> protection -> N900-internal

there's little use in doing sth like

Code:

your-protection -> $random-cable -> your-connection-to-testpoints -> N900-internal

Also without proper tools and experience/expertise you'll fail on that approach as much or even worse as/than you'll fail on the suggested proper fix of USB receptacle, as shown in the thread linked to in a former post of this thread

/j

Originally Posted by joerg_rw

The protection is to isolate $random_cable introduced mess from N900, as

Code:

$random-cable -> connector -> protection -> N900-internal

there's little use in doing sth like

Code:

your-protection -> $random-cable -> your-connection-to-testpoints -> N900-internal

Also without proper tools and experience/expertise you'll fail on that approach as much or even worse as/than you'll fail on the suggested proper fix of USB receptacle, as shown in the thread linked to in a former post of this thread



For a general note and advice regarding these testpoints: they are fine for using a properly designed service jig mount or sort of cradle to contact them. They are also ok for an emergency recovery setup, given you make sure there are no wrong signals, static charge, wrong voltages and/or polarities and so on. Most important: Alsways make sure to first connect the GND of your auxiliary contraption and the N900 GND, to avoid static discharge smoking up N900's chips


/j

Originally Posted by vertigodragon

so if i understand this correctly...the safest way to provide the +5V is from the original usb pad since it routes it through the circuit protection..BUT we can also rebuild the circuit protection but then we deal with the issue of the connection from the circuit protection to pad..or we can just connect directly to the pad and suffer massive consequences if something goes wrong

bottom line: the only viable way to provide power is through the original route?

Originally Posted by joerg_rw

Exactly. And same applies for D+/- to a slightly reduced degree
Though, as mentioned, a properly designed connector jig similar to the one 2 posts above with a few improvements, that also cares about ESD and protection at large, will work as that's what the pads are made for. Soldering some wires there and routing them to a USB receptacle won't pan out in the long term.


[edit] Thanks to suggestion 2 posts above, and of course thanks to those nice fellows donating to h-e-n, I ordered some of those connectors, let's see what we can do with some modding. Just in case you feel like donating as well, here's some Donate button

/j

Originally Posted by luketanti

Hello. I tried to solder the usb port how the other tutorial described but the data pins chip's 2 connectors broke as well. Can I use the two mentioned pads for data lines and still use the old +5v and GND. If I understood well I will be keeping the protection for the 5v but loosing only the esd protection.