iPhone Xr 0.03a No Power

[penhitech]

Hello,

Diode Mode is 0.00 in VDD_main, with PA_LB_K and Yangtze off.
Sorry though I would help with my observations, but yeah that is my current reading.
Thanks again.

[Jessa_the_Professa]

Okay, you have a short on vddmain. Solder a wire to any component or pad on main and inject up to 4v. Use a thermal camera to see if there is any heat. What do you find?

[penhitech]

I soldered a wire on vdd main and injected 4V, nothing is happening on my DCPS 0A, no heat, nothing, but 4v is present all over vdd main components.
Tried regular battery fpc connection through DCPS, same thing nothing!
The short is still active in VDD_Main.
I put back Yangtze again, still the same thing, PLUS short on PP_VDD_MAIN_YANGTZE also (Either with Yangtze on or out)
I don't know what's going on anymore, I think It is getting worse.

[Jessa_the_Professa]

One problem at a time. You either have a vdd_main short—but your wire and dc power are not attached, or you don’t have a vddmain short. If your multimeter truly reads 0.00 in diode mode with red probe on ground, then it is not possible for injected 4v into vddmain to consume 0A. Something is wrong with your process.

step one: remove Yangtze. Leave it off until you solve this problem. we never add new variables to a problem.

step two: measure vdd_main in diode mode with red probe on ground. You have claimed your reading is 0.00
now prove it, show a photo of the multimeter and tell me exactly where you are putting your probes. Measure two vdd_main spots because something is wrong with your results. Report both readings.

[penhitech]

Hello,
Yes, you are right, it did not make sense to me either, my power supply cable for iPhone 8(which powers up iPhone Xrs) was torn down and was not conducting current at all, I have just ordered new cables again.
It was not my intention to add new variables to the repair, I thought Yangtze was required for the boot sequence, sorry about that.
So yes vdd main is 0.00 in diode mode, and I am using my multimeter probs to inject 4V on the board .
Also, red probe on ground and black probe on L5500 reads 0.00 also on C232_W I have the same result.

Thanks for being so patient with this, and please find attached the videos you requested, hopefully, I did what you asked this time.
https://streamable.com/b9an9k
https://streamable.com/ko260d

[penhitech]

Hi,
I decided to give up on this iPhone, I also told the customer that I Could not recover the data from it.
Thank you for your assistance and for your help.
I will post again, if I need help for a different device.
Regards!

[Jessa_the_Professa]

Apologies, I missed your prior update. To look for heat with a full short on main, do exactly this.
1.) Solder a wire to the vdd_main test point near the top of the board.
2.) Use alligator clamp to clamp to that wire
3.) Alligator clamp to ground somewhere on the board that is metal.
4.) Set power supply to 1v and confirm that you have current draw
5.) Pulse the power supply by disconnecting/reconnecting the red lead again and again.
6.) Use the thermal camera to look for heat that is pulsing.

[penhitech]

No Problem Jessa, you did more than enough, I guess I screwed it up during shield removal for sure, so far I gave up on it.
Thank you for your help again and for your assistance.