Any tips to check on a dead iPhone 3GS?

Hi all,

My mums iPhone 3GS recently died, it's had a hard life this one, dropped a couple of times and has a non genuine back, but the screen etc are all fine.

Anyway, recently it powered down (didn't see it myself but sounds like it just ran out of juice) and refuses to power up again.

Yes it has had a few knocks but nothing recent, in fact it's probably had better life since the new back than it had in it's original apple shell.

My first thought was perhaps a loose connection from the back being replaced, so I followed one of the many guides and took it apart, checked it all and put it all together again, TNA.

Now I'm wondering if the battery may have just died, perhaps she didnt notice it wasn't charging in the last few days of it's life?

I'll grab another battery to test it for her, but anyone else got any suggestions that might be worth a shot?

I should say I tried simple stuff like holding power button as per apples instructions on resetting the device before I looked inside. Also I didn't just go to apple with it as she's already had it opened so I assumed they'd laugh at me at refuse to sell me an iPad in future or something

There are currently no signs of life, no noise, display or vibrate when connected to multiple power sources and not recognised by 2 macs.

Same thing happened with mine - battery ran out, and it wouldn't switch on again. The battery wasn't showing any voltage on the phone side of the protection PCB (the little board taped to the cell). When I bypassed the protection PCB to charge the cell with an outboard li-ion charger, it gave me a bad cell error, so the battery had died.

Took it into the Apple store and they exchanged it for a shiny refurb one for £55...not sure if they'd moan about the non original back though. Might be worth buying an original one on ebay and fitting that, just in case. They didn't check the internal tamper sticker on mine when I took it in.

It's worth leaving it on charge overnight though, in case the battery's gone into deep discharge. From my pokings, the phone appears to apply a quiescent current to the cell when the charger's attached and the battery isn't present or the cell voltage is below threshold. Presumably this is to revive a deeply discharged cell, assuming the protection PCB hasn't cut it off altogether to prevent further damage. So yeah, put it on charge overnight and try the home + power reset again...might revive the thing.

Try leaving it on charge for a logn period of time (eg overnight or while you're in work) before taking it to Apple.

Refuse to sell you an iPad? No, just no.

Cheers, I've had it on charge for over 24 hours now, no visual sign of life.

I say visual as if I hold the phone to my ear I can hear something, like maybe a faint buzzing noise. I assume that means the dock connector is fine, so prob the battery or connection from battery to main board I guess.

Well a battery is cheap enough to try, hope to have one in next day or so, if that doesn't do it then think I will look at off-loading it as it could decend into basically replacing everything and before I know it, we could have just bought a second hand iPhone that works