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-   -   iPhone 3gs, what chip is damaged? (http://forum.gsmhosting.com/vbb/f631/iphone-3gs-what-chip-damaged-1120272/)

tobygoodbar 10-19-2010 18:14

iPhone 3gs, what chip is damaged?
 
i have an iPhone 3gs that no longer charges or syncs. It will still work with dock port accessories such as an FM transmitter. If turned off and connected to its usb cable (wall charger OR computer) it will turn itself on everytime. If turned off it will "trickle charge" very very slowly, approx 50% in 24 hrs.

This happened after a specific incident. The iPhone was plugged into an iMac's firewire port with a usb adaptor. Nothing seemed to happen, and afterwards an external hard drive was tried, and nothing seemed to happen. so everything was reconnecred via its normal USB ports but neither device was recognized any more. evidently the usb controller board for hard drive was fried and something of the iPhone's was too.

So what needs to be replaced?
my own research leads me to believe either the pmb6820 or the ltc4088-2.

What do you all say on it? where should i proceed?

tobygoodbar 10-21-2010 06:11

78 views and no comments.

if i DID find out which IC to replace, are they need soldered or reflowed?

vascof1 10-21-2010 06:17

first thing check fuse, yesterday had same problem after car charger

br

tobygoodbar 10-22-2010 03:11

hey thanx for response. really.

anyway, fuse? what fuse? or more importantly...where? ive never noticed one anywhere in any of these phones before.

alexlaboratory 10-22-2010 03:23

NOW, two things you must do first

1- change your battery
2- change usb flex
3- check the following on the pic

http://img245.imageshack.us/img245/4735/charging3gs.jpg



Powered by **** team
br
Alex

tobygoodbar 10-22-2010 03:31

have already changed flex cable. in fact i changed the entire dock port assembly this afternoon and no change.

how do i check the fuse?
visually, or with a multimeter?

alexlaboratory 10-22-2010 03:34

Quote:

Originally Posted by tobygoodbar (Post 6475523)
have already changed flex cable. in fact i changed the entire dock port assembly this afternoon and no change.

how do i check the fuse?
visually, or with a multimeter?



you have to check with multimeter but id you dont have one just make a link in the charging fuse

tobygoodbar 10-22-2010 03:36

no i have a multi meter. so all i need then is a continuity check right?
i'm gonnna go get it now.

assuming the fuse IS ****n, do i just solder the gap or is replaceable?

alexlaboratory 10-22-2010 03:38

just solder a link, bare in mind no more protection after ;)

tobygoodbar 10-22-2010 03:42

much thanx. i'm going to get to work on this and then i'll report back

tobygoodbar 10-22-2010 04:10

http://img408.imageshack.us/img408/2...g3gspinout.jpg

Uploaded with ImageShack.us

ok it looked like you wanted me to test the poles that i re-labeled with numbers. i wasnt sure if it was 2 fuses or the 2 legs of a fuse on the other side. anyway in ANY configuration all labeled poles showed continutity.

the green fuse near vibrator also showed continuity.

are the 2 smaller items near what i labeled related? because they had different readings which i won't list unless it matter

alexlaboratory 10-22-2010 04:16

OK just change your battery then....they are cheap ;)

tobygoodbar 10-22-2010 04:26

i didn't remove the board for testing i just left it screwed into its housing. (just thought i should mention. don't see how would make a difference but just in case...)

anyway, you really think its the battery?
i only ask because the phone WILL turn on and function perfectly minus the fact it won't sync via cable or even be recognized. i would think syncing and battery would be unrelated, no? and secondly, if the phone is turned off and left on the wall charger it will gain SOME charge, very slowly. maybe 30% in 24 hours.

but just to clarify the phone doesn't ever acknowledge that its receiving any current, meaning no beep, or batt icon change. although if turned off and put on the charger it will turn itself on. but thats it.

alexlaboratory 10-22-2010 04:32

Ok no worries

I want you to do this, "see in the pic you marked 1,2,3,4 i want you to link(short circuit 1 and 2

tobygoodbar 10-22-2010 04:52

Quote:

Originally Posted by james2 (Post 6475631)
Seems the problem started here what is iMac's firewire port with a usb adaptor.

i mean besides tx,rx,gnd and Vp what those it do.

it allows you to plug in a usb cable to a firewire port. ...or in theory. i think it was ACTUALLY meant to plug in a firewire DEVICE to a usb port. there was non documentation with the product so i figured this must be what it was intended for AFTER the fact. so voltage from the computers firewire port went somewhere it shouldnt in the iphone.

Quote:

Originally Posted by alexlaboratory (Post 6475615)
Ok no worries

I want you to do this, "see in the pic you marked 1,2,3,4 i want you to link(short circuit 1 and 2

just to clarify, ok so solder 1 to 2 or use a jumper wire right to link them right?


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