Re: A novel idea to fix the USB port
 

Micro USB is so small with the tiniest pins for 1A or more to flow through.

I just want to say the tolerances on the micro USB ports I've used (nokia ones) are very close. The fit is very snug. So, maybe in those mating cycle tests there is the understanding the mechanical purchase one might have on the socket is taken up by the socket rather than the interface as is the case with bog standard full-size USB ports. You know, the full-sized plugs float around in the socket. The snug-ness of the micro USB connection might prevent damage to the actual pins? Just a thought..

Re: A novel idea to fix the USB port
 

Well, in our case, tooths and plug itself is filled a little (if user care about port safety), so plug is "moving" inside socket pretty easily. Despite this, no problem with 1250 mA going through those small pins, completely 0 problems.

It would be ideal, if not for stupid, *****ic way of mounting it to PCB. Sure, I can understand, that they may not want holes in PCB, for various reasons. But, if yes, why another industry standards - like one used for audio-video jacks, that have 4 pins already - isn't used?

Yes, i'm talking about this spring-pad solution, that made audio-video port on N900 virtually indestructible. Same apply for speakers connections. Basically, for freaking everything inside N900, except for microUSB port.

Sadly, it's also the case for most other devices. sure, they ports may be stronger (or weaker, in some cases), but overall, surface-soldering for thing like port can *never* be trusted.

/Estel

Re: A novel idea to fix the USB port
 

From what I've seen, the fact that full-size ports aren't super-snug is a big plus. If everything is completely snug every little movement of the plug gets transmitted to the socket; if it's floating around a bit, there's some leeway before the socket mounting points have to withstand significant force.
As for the solidity of the electric connection, USB type-A is surprisingly resilient; the size of the contact pads has a lot to do with this.

I concur. It's a good idea in theory, but it's useless unless the ports are soldered through-hole. I wonder who the hell thought it was a good idea to replace through-hole miniUSB with anything surface-mount, regardless of the shape and mechanics in the port itself.
Also, I don't really see the necessity of moving away from miniUSB; the shape is small enough for everything that can mount microUSB and the keying of the port is unmistakable, whereas microUSB keying can still be mistaken if one is not careful.

I had no other choice. I tried routing the cables around the camera module, but the casing wouldn't fit. I tried putting them under it, but then the module itself wouldn't stay in place, and again the casing wouldn't fit. It soon became clear that some plastic had to go.

There is less risk of damaging stuff by cutting off casing plastic, which is essentially inert, than by removing material under a board that must stay in its position if the camera is to work properly. I could have placed some tape or something where I cut the casing plastic away, but I don't particularly care how the device looks when the back cover is removed. Or indeed when it isn't, otherwise I wouldn't have a big glop of melt-glue on the side of it. :p

Not at all, what I have in mind concerns the battery. It's a surprise. :p

Ok then, let me put it this way: I'm hoping someone comes up with a way to install Linux-based systems in devices originally meant to run Android.
We've only got marketing to thank for the impossibility of doing this today, as the devices themselves are more than capable if the locks are defeated and drivers are available. I'm hoping enough lock cracking and homemade driver writing happens to allow this to work. I'd gladly help if I had any programming abilities whatsoever, but I don't, so I hope. And as they say, hope springs eternal. :)

Re: A novel idea to fix the USB port
 

Plastic under secondary board can be easily removed completely - and indeed, once I've fixed secondary board via two-side adhesive. worked great, and created much space for relatively "big" (in diameter) cables.

Of course, if Your way works for You, it's absolutely OK - I've posted above, just as tip for others, who may want to follow "full-sized-port way, without deforming N900's case too much (or, particularly, want to do cable's method. It seems to me, that if someone is determined enough, it's possible to avoid cutting any plastic at all (other than removing plastic thing'ie from secondary board, as mentioned earlier).

/Estel

Re: A novel idea to fix the USB port
 

Hmm. If I get any more N900s with broken ports I'll give your way a try. :)

Re: A novel idea to fix the USB port
 

Just a little aside. I measured my Nokia AC-10u 1.2A charger. Slit open the cable--stuck a Fluke meter in between. My charger maxed out at 650mA. I just had a feeling it wasn't actually charging a li-ion battery at or near 1C almost exactly 0.5C. I made sure my battery was well discharged before I measured.

Hmm...

Re: A novel idea to fix the USB port
 

That will be the charging controller in the device, not the charger.

Re: A novel idea to fix the USB port
 

Why? When under the same or similar circumstances I am seeing 800mA from my own home-built solar charger.

The way I understand the charging process is the charger is tested by the phone along the way. First second or two, to see if it can supply more than a couple of hundred mA. The charge is kept at approx 500mA for a few seconds, I haven't timed it but it seems like around 5 seconds, maybe 10. There seems to be another check after this to see if the charger can supply more.

There are kernel messages seen in dmesg | tail at this time too.

The only way I can see this charger is supplying 650mA is because that is all it is able- / limited- to supply

1C is quite a significant charging rate.

Re: A novel idea to fix the USB port
 

Are you sure the multimeter isn't adding resistance? Best way to measure this would be to gut a USB cable, short the data pins, connect the power ones to a laboratory power supply set to 5V and see what the current meter says.
I might do that if I can muster up enough willpower to start tearing apart USB cables again.

Re: A novel idea to fix the USB port
 

When talking about 1250 mA charging, I use custom 5V 2A charger, and I've tested before, that it actually can supply so much power. no idea about stock N900 charger, but it shouldn't be *that* lame (650 mA?!). Maybe this certain unit is malfunctioning?

Can't say for sure, as mine died (erm, helped it a little by screwing modification) some time ago, and I don't remember if I measured charge while using it. Since that, I'm always charging via mentioned 2A unit, or 50A modified ATX power supply (made from desktop PC ATX PS unit).

/Estel