Iphone 4 with not sign of life. Please help me!

[peppoR6]

I see you all are geeks about iphones.
I am an electronic engineer who loves to repair things but i have not the knowledge you have!
Here my problem..an iphone 4 with battery connector previosly removed.
Previous owner has tried to make direct jumpers to battery. I have removed all the mess he did and installed a new battery connector.
If i check continuity between pins of connector and "test point" like i saw in many posts of this forum, this is positive and i find correct voltage on pins of capacitors on the right of the connector under metalic shield (point red and yellow of similar post in the forum).

My problem : This iphone does not look at all oxided. IT is very clean. But, it is not recognized by itunes and it does not give any sign of life.
It does not make appear even the recharge icon. Nothing. No sign of life.
I tried all, with battery, with wall charger..nothing.
Yesterday I have also soldered a USB cable to + and - pins of board and once i plug the USB again I have the voltage (5V) right on the capacitor (point red and yellow of the post in this forum). Nothing is heating. I did this following suggestions i found on the forum. But Wites is telling me on private message to remove immediately this USB cable as likely 5 volts are too much..So i hope now to have not damaged even more this board.

One remark i can do is that just up the connector there are 2 filters (the very small ones)..this 2 filters i am not in the condition to say if they are working as they where in the middle of the mess made by previous owner. But they are in place. Any way to test them?

Another remark always testing randomly tensions over pins I remarked that there is a point where i guess i should have voltage and I have O volts.

All my remarks are contained in the image you can find here :
http://img29.imageshack.us/img29/8749/iphone014test.jpg

Please help me

I just need to know if there are simple test I can make to understand, why the iphone is not recognized by Itunes, it does not turn on, nor recharge.

Could be the responsible the PMIC broken?

Can i try to reball the PMIC ? if not, where can i buy a new PMIC for iphone 4? and of course...is it neccessary or you can suggest me ways to understand what is the real problem of this board?

Best regards,
Giuseppe from Italy

[peppoR6]

The image

[Wites]

Yes is possible that PMIC is burn but before replace it,try put dock flex and power on only by USB cable,also try with charged battery.
That 2 black filters right of batt connector check with multimeter if beep/short then they are ok.

[peppoR6]

Originally Posted by Wites

Yes is possible that PMIC is burn but before replace it,try put dock flex and power on only by USB cable,also try with charged battery.
That 2 black filters right of batt connector check with multimeter if beep/short then they are ok.

Hello,

I have tried with dock flex and powering with apple USB cable and it does not give sign of life. I will try to put this board on my working iphone with a charged battery to see if it works.
If it does not work do you suggest to change or reball the PMIC? if i have to change..where I can buy a working PMIC?

best regards,
Giuseppe

[Wites]

Originally Posted by peppoR6

Hello,

I have tried with dock flex and powering with apple USB cable and it does not give sign of life. I will try to put this board on my working iphone with a charged battery to see if it works.
If it does not work do you suggest to change or reball the PMIC? if i have to change..where I can buy a working PMIC?

best regards,
Giuseppe

Yes that is very possible PMIC damaged,if you reball it this depend if only phone was dropped.
Don't ask of who supply this ic's google.

[peppoR6]

Originally Posted by Wites

Yes that is very possible PMIC damaged,if you reball it this depend if only phone was dropped.
Don't ask of who supply this ic's google.

Ok Wites,

Do you have some test point i can check to be sure that PMIC is not working? I don't know..are there points on the motherboard i can check with voltmeter to be sure that PMIC is working or not?
Ok i will google to buy eventually this IC...do you know more or less the price?

thank you a lot
Giuseppe

[Wites]

Originally Posted by peppoR6

Ok Wites,

Do you have some test point i can check to be sure that PMIC is not working? I don't know..are there points on the motherboard i can check with voltmeter to be sure that PMIC is working or not?
Ok i will google to buy eventually this IC...do you know more or less the price?

thank you a lot
Giuseppe

Download full schematic here on forum and check if DZ1_PMU not short with GND also all coils check if are ok,don't ask for picture everything you need is in schematic.

[peppoR6]

Originally Posted by Wites

Download full schematic here on forum and check if DZ1_PMU not short with GND also all coils check if are ok,don't ask for picture everything you need is in schematic.

Ok sir,
I have the schematics that you put on the forum. Can you tell me
What does it mean that this dz21 pmu does
Not short with ground? Where I have to measure this short? Do
I find it in the schematics? Can't you tell me more? I am not
So practic :-( I can find this d21_pmu but do not
Know how to make this check of being or not grounded.

About coils do I check them checking that they are
Continuos? I mean 0 ohm on pins of coils.. Is
That the check or another?

Sorry to ask so much but please help me :-)

Best regards

[Wites]

Originally Posted by peppoR6

Ok sir,
I have the schematics that you put on the forum. Can you tell me
What does it mean that this dz21 pmu does
Not short with ground? Where I have to measure this short? Do
I find it in the schematics? Can't you tell me more? I am not
So practic :-( I can find this d21_pmu but do not
Know how to make this check of being or not grounded.

About coils do I check them checking that they are
Continuos? I mean 0 ohm on pins of coils.. Is
That the check or another?

Sorry to ask so much but please help me :-)

Best regards

You say right to check coils for continuity,to check DZ1_PMU switch to diodes testing,you not need photo that is board in schematic.

[peppoR6]

Originally Posted by Wites

You say right to check coils for continuity,to check DZ1_PMU switch to diodes testing,you not need photo that is board in schematic.

Ok i found this diode and I will cheek it!
DO I have to check all coils in all the motherboard or I have to check specific coils?!

Thank you again, Giuseppe

[peppoR6]

[QUOTE=Wites;8172689]You say right to check coilsn ; n
Hello here i am back!

So the result of my exploration :
Coils L1, L3, L16,L17 C269, C168 are all grounded
I tried to remove C269 and C168 hoping they were responsible of short, but once desoldered grounfing of L1,L3,L16,L17 is still there and checking capacitors C269,C168 with a ohmeter once they are desolderes show (correctly) no continuity. So where i have to look for the short to ground?

By the way to check the zener diode DZ1_PMU is NOT POSSIBLE! it is very little and it's SMD so contact are under the component. If i disolder it i will not be able to sold it back, because it is very little.

By the way I did a little mess. A drop of soldering mixture has dropped on the J8 connector..so trying to remove the drop even taking care finally connector J8 come out and also component FL16. May i replace FL16 with a short?

So please masters of Iphone help me to understand why this PMIC has its principal output (the ones toward L1,L3,L16,L17) grounded ?

Possible hints?

Regards!!

Peppo

[Wites]

[QUOTE=peppoR6;8175729]

Originally Posted by Wites

You say right to check coilsn ; n
Hello here i am back!

So the result of my exploration :
Coils L1, L3, L16,L17 C269, C168 are all grounded
I tried to remove C269 and C168 hoping they were responsible of short, but once desoldered grounfing of L1,L3,L16,L17 is still there and checking capacitors C269,C168 with a ohmeter once they are desolderes show (correctly) no continuity. So where i have to look for the short to ground?

By the way to check the zener diode DZ1_PMU is NOT POSSIBLE! it is very little and it's SMD so contact are under the component. If i disolder it i will not be able to sold it back, because it is very little.

By the way I did a little mess. A drop of soldering mixture has dropped on the J8 connector..so trying to remove the drop even taking care finally connector J8 come out and also component FL16. May i replace FL16 with a short?

So please masters of Iphone help me to understand why this PMIC has its principal output (the ones toward L1,L3,L16,L17) grounded ?

Possible hints?

Regards!!

Peppo

to clean connector use an stick with wool soacked in thinner,you can jump removed filter,that coils short because PMIC is short to check this connect charged battery and sense the heat,you can also try with charger but i not guarantee that it will heat with charger better with battery or power suply give 3.7V.

[peppoR6]

[QUOTE=Wites;8175790]

Originally Posted by peppoR6

to clean connector use an stick with wool soacked in thinner,you can jump removed filter,that coils short because PMIC is short to check this connect charged battery and sense the heat,you can also try with charger but i not guarantee that it will heat with charger better with battery or power suply give 3.7V.

Ok, I have all understood. A question : if the PMIC heat it means the only solution i have is to replace the PMIC with a new one or try to reball it?
many thanks Wites!

[Wites]

[QUOTE=peppoR6;8175805]

Originally Posted by Wites

Ok, I have all understood. A question : if the PMIC heat it means the only solution i have is to replace the PMIC with a new one or try to reball it?
many thanks Wites!

This depend if it was heated before but i think it PMIC burn when you give 5V with USB cable.

[peppoR6]

[QUOTE=Wites;8175881]

Originally Posted by peppoR6

This depend if it was heated before but i think it PMIC burn when you give 5V with USB cable.

I guess it would have heaten before to burn when i gave the 5 volts, but no...all was cold..so i guess that it was already died.

If i remove the PMIC is there tests, with multimeter, i can perform on the IC removed to see if it works or not?

Regards,
Giuseppe