Asus Rog GL703G/Battery Connector Short

[GlassMonolith]

Hi, all. I have an Asus Rog Strix GL703G. Yesterday I took it apart to clean out the dust and redo the thermal. Unfortunately, when I attempted to pull the battery, the metal retaining clip (unable to retain itself due to genius engineering) popped off and shorted across the capacitors behind it. Now I have no response from the laptop with or without the battery.

I'm hoping maybe someone can help me read the board and figure out what potentially shorted. I have a soldering station, I can run hot air, I have a multimeter, I just have no idea how to trace or measure the power circuit. I'm good at the physical part, but very iffy on the electrical engineering minded part.

I will provide photos of anything and everything request.

Thanks!

[GlassMonolith]

This is the area the clip shorted on.

[Sephir0th]

Take a picture of the whole board, remlve all power and collect resistance to GND measurements of each inductor present (any pad). Then repeat the same in DC voltage Mode, this time with power applied of course (plug the charger). Write the values in the picture and share it here.

[GlassMonolith]

Forgive the ignorance, do I measure from the power supply port, or the battery connector?

Also, there are regular pads, but there are also pads that have what look like solder balls all over them. I'm unfamiliar with these, do I measure those too?

[GlassMonolith]

Still hoping for some help here. 😁

[GlassMonolith]

Still still hoping for some help here.

[mon2]

The posted suggestion is to review the resistance to ground of each inductor. The inductors will often be grey in body color and will have 2 fairly wide solder pads. Inside each inductor is a large number of windings so essentially a coil. Remove all power. Meter in resistance mode. One meter probe to one side of the coil (either side is ok); other meter probe to ground (metal shield is ok). Note the measurement and post each resistance check here for a review.

[GlassMonolith]

Awesome, this was the elaboration I was hoping for. Thanks for that.

So I measured each inductor. I want to mention that I measured the ohms in auto and;
1: The inductor on the bottom nearest to the battery connector was very odd. Either side wanted to measure differently, and even touching a different spot on the same pad showed a different measurement. Sometimes it didn't even want to measure.
2: The inductor on the top-right nearest the power connector bounced all around M & K and wouldn't settle on measurement.

[mon2]

Can you clarify the resistance to ground of the inductor on the top right of the posted pic @ 0.0 ohms? Be sure the units of measure is correct. Short your meter probes - do you read the same reading as the inductor check?

If truly at 0 ohms to ground, you have a dead short here on this local power rail.

[GlassMonolith]

Yes, top right with power cable unplugged; reading was all over the place. Power cable plugged in; reading was 0.0 on both solder pads.

*Edit* so with my Fluke meter, unplugged that inductor reads wildly all over, but with my craftsman meter it will read about 135k. Both read 0.0 when plugged in.

[GlassMonolith]

Wait, I just re-read, sephir0th suggested metering with the power plugged in in DC VOLTAGE mode. I shouldn't have done metering with resistance than for that?

[mon2]

Correct. Never measure resistance or DIODE mode readings with power on. Remove all power / remove battery. Meter in resistance mode. Then measure.

[GlassMonolith]

Okay. So in the photo I provided with readings, the top numbers are metered with no power, no battery. The bottom is metered WITH power cable.

I'll measure the second number again in DC voltage mode.

[GlassMonolith]

Okay, here it is again with voltages (with power cord inserted).

Just to verify, just power cord in, or does the laptop need to be ON? There are a lot of "0.0v".

[GlassMonolith]

mon2 Thoughts? 😅

[GlassMonolith]

Still hoping for something here.

[mon2]

Review the mosfet that has the ~19 volts. Share the topside markings of this mosfet.

which other mosfet is nearby?

these dcin mosfets are enabled by a charger ic. This charger ic may be on the opposite side of the logic board. We need the topside markings of the charger ic.

[GlassMonolith]

The 19v mosfet is the one next to the charger port, with no other mosfets near it.

Second photo is opposite side of board.

[mon2]

Review the 2 mosfets with 8 pins and ‘Nikos’ topside markings.

With no power, meter in resistance mode, measure the resistance across the mosfets:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

post each measurement. Repeat for the next mosfet.

[GlassMonolith]

Okay, here are the readings for that top and bottom "Nikos" mosfet;

Top:
S+D = 4.8MΩ
D+G = 10.5MΩ
S+G = 4.6MΩ

Bottom:
S+D = 8.9MΩ
D+G = 12.8MΩ
S+G = 4.5MΩ

Additionally, I also measured a mosfet near the battery connector where the short occured (see attachment):
S+D = 26KΩ
D+G = 0.0
S+G = 0.0