iPhone SE no charging to no power up

[GuruFix]

Got a iPhone SE that hasnt been repaired at logic board level before. The phone was charging 0.9A and a minute later 0.0A. See diagram.
I decided to change tristar and tigris both. Used a pre-heater (175 degrees) and carefully replaced tristar and tigris. Used kapton tape and coins to protect HDD.

After replacement the phone doesn't boot anymore
0.0A before prompt to boot and when the device prompt to boot DCPS gives 0.04A - 0.05A - 0.06A.
No image/No backlight/No iTunes detection and no DFU/recovery detection

[Jessa_the_Professa]

Are you sure this SE needed tristar/Tigris and it wasn’t the common fault of missing gas gauge filter by battery? Missing gas gauge filter on SE is 90% of “charging problems”

You have a brain dead phone, and the most likely reason why is the tristar or Tigris job.

take both off, check for any missing resistors and see if the phone has a different dc current pattern without them

[GuruFix]

Yeah thats what i thought. My bad. Im checking it now

[GuruFix]

[GuruFix]

Jessa_the_Professa Removed tristar and tigris and removed all the black glue/mask/stuff. Everything looks fine and complete except its missing R2300 but that's NOSTUFF. When i prompted to boot with power button the phone is still brain dead 0.04A - 0.07A

At the battery connector the filter/caps are present.

[GuruFix]

Update: measured the resistors near tristar and tigris and they are all good.
Also no shorts have been found.

[Jessa_the_Professa]

This will be difficult to solve. You can trigger this situation, or the companion situation--steady 70mA--experimentally if you short the i2c lines from the CPU to ground. Did the tigris chip come off with any solder balls bridged under it? One explanation would be if main got bridged to one of the i2c lines under tigris and was then sent into the CPU. Other ideas are that something was overheated--this is a challenging repair. Are you SURE that this phone could boot before you jumped in to change tristar/tigris?

[GuruFix]

Jessa_the_Professa Yes the phone did boot before repair 100%. In fact this customer was a day earlier also in our shop with 0.0A. When we replaced the battery and the phone was charging just fine .9A. A day later the customer came back with the same fault.

When i think about it. At first i only did changed tristar and tried to boot. Thats when i saw a brain dead phone for the first time. This lead me to change tigris aswel because i've seen lots of videos where its tricky to replace only tristar. Maybe some solder balls bridged underneath tigris when replacing tristar? That possible, although i used kapton tape/preheater/coins.

Removing tristar and tigris went just fine as everyone likes.

[Jessa_the_Professa]

This will be difficult. There is no short, this is a data problem. You were soldering right next to NAND and using tape/coins and preheater. That is a lot of heat. I would not use tape or coins with the preheater--it will just reduce airflow and result in more heat being put on the board. If you don't see any physical damage and you're sure that tristar /tigris went well with no bridges under them then next you'd have to reball NAND. I would definitely try tristar tigris again.