HP VICTUS 15 FB1013DX.... DAG3PRMB8D0.... help with coil. probably ram coil of ddr5!

Greetings. I need help with a coil; it's probably the power supply line for the DDR5 RAM.

I've checked some posts here, but I haven't had much luck with the repair. Here's a step-by-step description of the problem and the repair I've done so far:

1. The coil IC was burned out. I replaced it with one suggested here, the SY8386BRHC.

2. I repaired traces due to the IC burnout.

3. When measuring continuity and resistance on the coil, I get continuity to ground, which shouldn't be correct as far as I know.

4. I checked the capacitors, and they're all fine, after the coil on that trace. They measure 22uF.

5. It's impossible to know what else this trace powers since it jumps to the opposite side of the board. I'm assuming it's the pins shown in the second photo. There are 11 pins. 6. The device is charging the battery, but I only have voltage at one coil, which is 5V.

7. When I try to turn it on, it attempts to power up, but immediately shuts down. The fans don't turn on.

8. Upon visual inspection, I found two damaged capacitors. One is for the audio amplifier, and the other is for the USB-C connector.

9. Continuity readings on the CPU coils are 3 ohms and 6 ohms.

10. Continuity readings on the GPU coils are 0.3 ohms.

I need help determining what other systems are powered by the 1.1V DDR5 coil, if it's the correct one, and what its function is. Is the IC I installed correct, and what other problems could there be?

Thank you.

Please post a clear, sharp and hi-res photo of burnt PCB with the nearest surrounding area. It may be the case that the short circuit is inside the PCB - it's quite common where the PCB's structure was burnt.

NANO002 napisał(a):I need help determining what other systems are powered by the 1.1V DDR5 coil

In case of pure short circuit you can do a so-called "short test". Please refer to this post in TRAININGS subforum (English version available when you scroll it down): post5699.html#p5699 - search for "short-test" phrase. This way you can determine what is actually causing a short circuit to the particular power or signal paths/rails.

EDIT: I have removed the photos you added to first post as they are very blur and there is no possibility to see the details we suppose to see. Please post a CLEAR and SHARP photos of burnt area with its surrounding not exceeding 2cm. Please also add your photos to a NEW post instead of editing the first one, because the topic is missing a chronology.

Good day. My apologies for the photos. I took them with my phone for quick reference. I'll upload a new one now, taken with my microscope. I hope these are helpful. Regards.

Desolder SY8386BRHC chip and check if you still have a short circuit to ground on that 1R0 coil. If so, desolder this coil and perform a short-test (linked in the post #2) on the bottom pad (the one shorted to ground) to find the component which causes that short circuit. If the short circuit to ground has disappeared after SY8386BRHC desoldering, please post a clear photo of the area under that chip.

In addition, two capacitors need to be replaced on top. One marked with yellow arrow seems mechanically damaged (top pin) and other one marked with black arrow seems corroded (bottom pin).