After nearly 5 years of faithful use, surviving many drops and fumbles, the N900 has finally died. Well, it is at least paralysed. I'll explain.

I've always been careful with the micro-usb port, but never strengthened it in advance, as I see some have been recommending. That's a slight regret.

Anyway, it came off, so I temporarily glued it with fabric glue (easy to remove when it came to actually soldering) to get some charge into the battery, considering external chargers first but ideally wanting a working on-board charge.

The next day I took it to a friend who could assist with the soldering job. Managed to get it firmly attached and was about to test when we decided to just quickly make sure the 5 USB pins were soldered, just applying the heat for belt and braces.

Well, it was either the first solder effort or the final 5-pin touch-up, but on attempting to re-boot the device I got the white LED and the screen backlight but no OS displaying. Not even the loved/hated 5-dots swinging back and forth. Then my custom email notification LED alert came on a minute or so later. The phone is alive in there, it just can't display to screen -- basically paralysed. The alarm still goes off, notifications show etc. but nothing on the screen.

- What, I wonder, could have caused this?
- Did we touch something we shouldn't have in the solder job?
- Could the board have been overheated, frying a display component somewhere?
- Is it really bricked?
- Could putting it in the oven be worth a shot at this point?

I have looked over the screen and other components, but can't see anything untoward with the naked eye.

I attach some shots of the connector, the soldered area (post-scraping between connectors to ensure no shorts) and one from the more exciting work-in-progress stage for fun. That one features the friend I mentioned, who I usually have to defer to for any electronics questions/advice.

EDIT: Just to let you know I have replied, but those replies are still in the moderation queue - new account... Thanks for suggestions. Replies ask if you both mean the connector between the detached body and screen parts - the main screen connector, I'd call it. I did notice a slight bit of damage to the pins there, so it could be the case. I'm on ebay for a spare now.

Without trying to get your hopes too high, I am getting the impression that your phone is working fine, only the display misses the connection to the main board. It is easy to not push the connector back in properly and I think that that is the problem. Try to open it again and fix the connector.

Edit: I mean the display connector, not the USB connector. I thought it was obvious but just to clear any potential confusion...

Aww thanks for that. Kind of thought the same, but after stripping it all down and reconnecting the screen connectors, it *seems* that the problem's elsewhere. I still hold out some hopes in that respect, but it's hard to diagnose, and it did happen immediately after soldering (it worked before the solder job. The only other thing I can try on this front is to clean out the connection to the main board before re-attaching.

I do wonder if 10 minutes in the oven wouldn't help or just further brick the thing, if that's possible.

Just to follow up -- I did have another look and there is the slightest chance that the connector on the screen's ribbon is minutely damaged. The pins could be ever so slightly retracted on a few connection points (from a few fumbled attaches possibly) so I could test a new screen to be sure... [heads over to ebay]

Yes, I would try the main ribbon connector first.
It is very delicate and is a bit of an art to locate correctly.

Thanks both. So we're saying the main connector from the board to the 'detachable screen section'?

I have some replies in moderation still (new account after years of lurking), basically saying there's a chance this could be the one that's damaged. Will buy an n900 for parts and swap it out. Fingers firmly crossed.

Just to let you know, as edits to first post might have slipped unnoticed - OP tried to reply, but all his post are still waiting for moderation...

/Estel

I somehow read the title as "Soldier finally kills N900, its his job".

All I could think was "why???"

-- FIXED --

By replacing the main screen<>body connecting ribbon, at cost: £6, the phone display is back in action. No soldering damage then!

Now to try and get the microusb back in place safely. Worth scraping the copper rails out, or too risky at this point?

Thanks to all for your optimism and hacker/tinkerer spirit. One happy N900 user still in the game.

To think I was about to prepare to buy a Ubuntu phone. OK, I'm still quite taken by the idea of a convergent phone/PC, but that at least can wait now!

PS: @Kangal - to be clear, I'm not a soldier

I've always thought that putting an N900 (even if just the mainboard) in the oven is a half baked idea myself.

People fret about overclocking the CPU, so submitting the whole board to temperatures 3x as high seems risky. Then again, I suppose as a last resort...

Congratulations on fixing the N900, BTW. The N900 soldiers on and lives to fight another battle.