Back on track...

Da what? Of course, you're convinced that drop of <whatever>liquid killed it, *not* incredibly stupid idea of heating GSM chip via soldering iron? Really? What was that, a brainf**k attempt at "reflow"?

Despite epic facepalm, I still think it needs further commenting, in case anyone *ever*, may want to attempt something like that again. I'm speechless. Lets even put aside fact, that *any* attempt at reflow without proper tools is extremely risky, and should be done *only*, if you don't have anything to loose with that particular device.

Now, if that would be the case, the *only* way with at least slight chances of success, is to remove every plastic part humanly possible from motherboard (including keyboard matrix), and put such barebone'd motherboard into ~230 C degrees oven, for ~8 minutes. Then, disable oven, open it, and let motherboard cool down slowly, without taking it out, until it's @ room temperature.

No guarantees, that it will work after that, at all. but there is slight chance - unlike doing it with soldering iron vs. chip itself, which is as much idiotic idea, as it goes. No device have right to live, after that. Attempting it is mark of requiring education about physic at level of basic school (late classes), let alone any university exams.
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As for flex between secondary board and mainboard, I can perfectly imagine how you've torn it. Well, once, with one device, I did it myself - not because "device was stupid" or "life sucks", but because I was frikking not careful. My fault, not anyones else or "bad luck". Those things is far from being bulletproof, and in case of de-glue'ing it from mainboard, it should be secured (for example, using *light* tape) in one position. Allowing it to move freely, even a little bit, is a road to disaster. Took my lesson, and I'm always securing it, now.

/Estel

Sounds like karma to me.

So to summarize:
You have to cheat on your exams to get some money for getting good grades, and the n900 is the best tool for that for you.

Here's two suggestions:
1. Don't cheat; study. You'll be better for it in more than one way.
2. Get a part time job, or a student loan, like almost everyone else in the world does.

Good luck!

Not defending the guy. But it sorta indicates that the whole gnome thing is so brokenly designed that not even as CS graduate can make sense of it.

That is just ridiculous.
I lost my N900 and I didn't complain and make silly threads about it.
And one more thing:
I treated it like it was supposed to be treated, unlike you..

I dont get it. How can someone heat a BGA chip with soldering iron?
The only way to do that is with a hot air soldering station (i do that everytime my playstation 3 throws an ylod error).

In case of N900, even a heat gun would be hard to implement in practice (Not much space to heat only what you want to heat). Only "proper" way would be using IR heating station (which can heat certain parts accurately to parts of millimeter), and non-proper but -might-work is using oven.


I don't even want to imagine how one could attempt to heat a chip using regular soldering iron. It's terrific.

/Estel

Yes, but an IR soldering station can be expensive and hard to find. But with a hot air station and a proper small noozle, it had a chance. However who want to do that has to know the max temperature that n900 motherboard support. Anyway this is only reflow, for a proper fix it would need reball with lead tin, becase i think (but not very sure) that n900 uses lead free tin.

I haven't seen it myself, but read somewhere on the web like someone was horrified by seeing his coworker fixing SMD chips with a soldering iron. He would just take the board with the chip on, the iron, a lot of flux and simply run over all the pins. Side to side, you understand. Not one pin at a time. All of them simultaneously. Somehow it worked. I would dare to do that f I had nothing to lose, luckily haven't had an opportunity to try yet.

aaa, yes, that trick work with SMD chips that have pitches (even fine pitch), but no way with BGA SMD chips. As far i saw in n900 mb pictures those gsm chips are fine BGA.
As for chips with pitches is easy and logical to use a soldering iron - even for replace - after the old chip is removed, the new chip must be placed on the right pads, every pitch must touch its right pad, after that solder the top rightmost pitch, then the left one and the run over all pitches with lot of flux to ensure there is no short circuit. I did that on an old pc motherboard and it is still working

As soon as wil find someone with a decent camera i will post some pictures with my modified n900. i dont think anyone has done this modification before i will say no more

BGA... I missed that tiny detail