IPhone 6 Plus not booting

[Kgn]

I have one iPhone 6 Plus customer bring it as it is, I checked voltages and everything look fine but when battery connecting it’s charging amp go up to 1.10 but when press power button it’s go down to 0.08 and not booting when press home button and connect to iTunes it’s detecting in iTunes I replaced Tristar but still same ,

can see touch ic been replaced befor ,

anyone know now what could be problem?

[crea2k]

Have you tried another battery ?. It is very odd behaviour

[Kgn]

Yes I tried another battery also with dc power supply dc power go up to 0.15 0.18 that’s it nothing more some one have replaced Touch ic before but it’s clean I don’t think it could be a problem, I am trying to restore it but this way also not helping no display or backlight , backlight voltage present but just for a second and then nothing,

[crea2k]

Iv seen phones go dead because of a bad touch ic job, but usually that is apparent straight away, not a long time after. You could always try compare the touchscreen connector diode measurements to a known good board. It won't rule out all meson lines but it will give you a rough idea if you need to check these.

[Kgn]

Ok let me check if help thanks for helping

[Jessa_the_Professa]

The problem isn't clear here.

You said "not booting" but you also said "will connect to iTunes"

Do you mean "This phone is autobooting to DFU mode and iTunes is detecting it in recovery mode, and it has no display as is typical of a phone in DFU"

If so, then restore. The phone may not have a hardware problem at all, it just doesn't know what to do. The instructions are missing.

[Jessa_the_Professa]

To be clear---A phone that can't understand its software will automatically boot to DFU mode by itself.

A normal phone in DFU mode:
Will sit at ~70mAmps on DCPS
Will have power voltages present as normal
Will consume ~0.09A on usb ammeter
Will have no image

Do not spend time trying to troubleshoot normal features of a phone in DFU mode--i.e. a phone in DFU mode does not have an image problem, it has no image BECAUSE IT'S IN DFU MODE. Try to figure out why it is in DFU by kicking it out via Re-iBoot, or update/restore.

[Kgn]

It’s not in dfu mode and it’s not booting normal also but in my testing if I connect iTunes it’s not connecting but if I try to connect with DFU it’s detecting

[Jessa_the_Professa]

So the problem is the phone is no power, meaning it will not boot and is not detected by iTunes.

To troubleshoot a no power phone, start with DCPS through battery connector. Report the behavior before and after prompt to boot.

Usb ammeter tells us nothing for a phone that won’t boot, it only helps us with a phone that can boot but not charge.

If a phone can’t boot but it can go into recovery mode, then restore after changing tristar. What error do you get?

[Kgn]

no error when iTunes resat phone and waiting for phone to come on its not coming on , and just waiting for phone to come on that's it no error nothing usb line voltage 3.76 vcc main with usb 4.25 with battery almost same all voltage are present, not understanding why its not booting then i am looking for fault where to start from

[Jessa_the_Professa]

This still isn't clear to me.

The phone can go into recovery mode and iTunes detects it? Then you click restore and the phone shows a normal display with progress bar? Then the phone completes restore with no error, and when it needs to reboot to 'load' the update on the phone side----it does what? Sits there with blank screen and is never detected by iTunes in normal mode? What is DCPS behavior at this point?