iphone 7 no power no image

[Thedan55]

Hi everyone. I've got an iPhone 7 with no power. I'm not too familiar with phone board issues would appreciate a little guidance if you can please.

When connected to my PSU is cycles between0.007 to 0.178

With charger connected to lightning i get no voltage on battery connector.
Battery connector plus to negative no short. while charging stuck at .44a no change with new power button flex and charging fles.

phone is recognised in itunes when i put it into dfu mode

Positive terminal diode reading is.478

tested the digi fpc in diode mode comparing with bv measurements
Pin 1 says 505 im getting 263
Pin 3 says 573 I'm getting 245
Pin 25 says 746 im getting OL (looking at bv its not supposed to be ol)

any guidance would be immensely appreciated please!

[mon2]

Re: iphone 7 no power no image

Watch this video for some ideas:

https://www.youtube.com/watch?v=ZmMg...WFSuKVl4AaABAg

[elecsoluces]

Re: iphone 7 no power no image

Phone is recognised in DFU mode so try restore via itunes (you will lost data) or try an update with 3utools to save data.

[Thedan55]

Re: iphone 7 no power no image

Watch this video for some ideas:

https://www.youtube.com/watch?v=ZmMg...WFSuKVl4AaABAg

Will do thanks

[Thedan55]

Re: iphone 7 no power no image

Phone is recognised in DFU mode so try restore via itunes (you will lost data) or try an update with 3utools to save data.

I can't loose data it belongs to a customer

[Thedan55]

Re: iphone 7 no power no image

Plus no image

[Thedan55]

Re: iphone 7 no power no image

so ive not found any shorts on the board. ive injected but as you might guess no power draw.

i found cap C7606 practically off the board, barely is connected, i can nudge it and its moving. not taken it off yet.

this board has been worked on by someone before me so its difficult to know whats been done.

the area at the bottom end of the board is missing a bunch of caps and filter. i replaced filters and resister from donor, someone told me C3823 and the 2 next to it arent needed for boot.

im honestly thinking this might be a chestnut issue, but it doesn't seem like its booting. while connected to psu its pulling .57 .62 .64 .78 168 and a few more then goes to 0 then does it again.

i really have no clue at this point. can anyone help please?

[mon2]

Re: iphone 7 no power no image

You are power / boot cycling.

Review each and every power rail to confirm that each is present.

Before proceeding, remove all power -> meter in resistance mode -> check the resistance to ground of each of the above power rails.

A shorted cap can cause this fault. Check for any low resistance on the power rail.

Rewa (Shenzhen) has great videos on phone repairs.

[Thedan55]

Re: iphone 7 no power no image

You are power / boot cycling.

Review each and every power rail to confirm that each is present.

Before proceeding, remove all power -> meter in resistance mode -> check the resistance to ground of each of the above power rails.

A shorted cap can cause this fault. Check for any low resistance on the power rail.

Rewa (Shenzhen) has great videos on phone repairs.

Thanks will do! Appreciate it

[Thedan55]

Re: iphone 7 no power no image

You are power / boot cycling.

Review each and every power rail to confirm that each is present.

Before proceeding, remove all power -> meter in resistance mode -> check the resistance to ground of each of the above power rails.

A shorted cap can cause this fault. Check for any low resistance on the power rail.

Rewa (Shenzhen) has great videos on phone repairs.

right so while testing the power rails i got to vdd boost and found an issue. c3828 has both pads missing, one side which is vdd boost goes into u3801 which enables a bunch of things from what im seeing, touch, pp2v75, mamba meesa.

the cap c3828 has lost both pads. can i life u3801 and run a jumper from its vdd boost pad to recreate the point for the missing cap?

Also on pin 4 of the touch connector i get ol which i think i shouldn't be getting. But u don't think that's affecting the boot cycle. But I'm not certain

[Thedan55]

Re: iphone 7 no power no image

Added image

[Thedan55]

Re: iphone 7 no power no image

Anyone?