Asus Rog GL703G/Battery Connector Short

[mon2]

To me, that is a low resistance. For giggles, flux and remove the cap that is on this rail. Then measure the resistance again on this pin.

[GlassMonolith]

mon2 Okay, so I took off the cap circled in the photo. Still measured 50ohm.

On an unfortunate note; I managed to accidentally swipe off an additional cap (as seen in photo) and have no idea where it even went (I cleaned my iron tip before realizing it was gone). Hopefully it's easy enough to figure out what cap to replace it with?

[mon2]

Yes, we should be able to determine the missing cap details from the datasheet of the bq24780s charger ic.

Meter in resistance mode. No power to the board. Measure the resistance from the top pad of the missing capacitor to each pin on the charger ic. Stop when you find the pin that shows ~ 0 ohms.

Also, carefully flux and remove the sot23 3 pin part with L43 markings. Do not lose the part.

Then measure the resistance to ground again of this REGN pin. Still at 50 ohms?

[GlassMonolith]

mon2 Okay, I measured every pins resistance, and the one with 0 appears to be pin 18. I'm going to work on pulling the sot23 in a couple hours.

[GlassMonolith]

mon2 Okay, with sot23 off, still reading 50ohm.

[GlassMonolith]

mon2 Thoughts?

[reformatt]

Replace the BQ24780S IC.

[GlassMonolith]

reformatt I figured, at this point. He was having me test another part of the circuit though (not sure what it was for), and I ended up losing a capacitor from it, so I'm trying to get info on what to replace it with as well as the info on those measurements.

[reformatt]

Cap on pin 24 is 2.2uf 16V 0603, pin 21 is 0.1uf 25V 0402

[GlassMonolith]

reformatt And just to verify, that's for the cap that measured 0ohm on pin 18?

Also, I'm seeing a couple results on Digikey. Does the Temp Coefficient matter?

Also #2... What's the difference between bq24780sRUYR and bq24780sRUYT?

[reformatt]

reformatt And just to verify, that's for the cap that measured 0ohm on pin 18?

According to the schematic, nothing is connected to pin 18. Pin 1 starts from the RHS where the dot is and counts counterclockwise. In your photo you have removed two caps, one is on pin 21, the other pin 24. X5R should be fine.

No difference between the two BQ chips - difference in numbering is just for tape and reel packaging. Check the datasheet.

[GlassMonolith]

reformatt mon2

Okay so chip came in and have it on the board. What can I check/test for safety before giving it power to make sure it's all good? Continuity seems to flow through a couple of legs, but not most others.

[reformatt]

Make sure pin 1 is where it should go and no solder bridges across pins. Sometimes QFN's don't make good contact with the board, that's why you touch up the sides with flux and solder with a micro tip. If the soldering contacts aren't up to scratch, it will simply not work.

[GlassMonolith]

reformatt Okay. With such a small chip, I wasn't sure if briging was possible underneath where I wouldn't be able to see. But it looks like I'm lined up pretty well.

[GlassMonolith]

reformatt mon2

Well, got it all back together, battery plugged in and power cable in and still nothing. Assuming you guys will want the same readings again off of the IC, so I can get those posted up tomorrow. Then anything else you'll want me to check?

[GlassMonolith]

reformatt

Okay, here's todays measurements.;

IC:
Pin 4: 0.1v
Pin 5: 0.3v
Pin 6: 2.7v
Pin24: 0.2v
Pin28: 19.5v

Results are slightly different than before, what could that mean?

[mon2]

Post a pic of the reworked charger ic.

Does the logic board boot with the power adapter?

Carefully(!!) measure the voltage to ground of each pin on the charger ic with the power adapter connected.

Post the table of values with each pin / function label.

[GlassMonolith]

mon2

Working on the measurements asap, but here's the photo.

[mon2]

Top view looks good but be sure that the writing on the replacement is 100% in the same orientation as the original.

Only then we know that pin #1 on the IC = #1 on the PCB.

Pour some alcohol onto the top side and share an angle pic so that the writing of the topside is visible. Only for inspection by the internet techs.

[GlassMonolith]

Full IC pin;

1: 0.90v - ACN
2: 0.90v - ACP
3: 0.08v - CMSRC
4: 0.08v - ACDRV
5: 0.05v - ACOK
6: 2.70v - ACDET
7: 0.00v - IADPT

8: 0.00v - IDCHG
9: 1.06v - PMON
10: 0.00v - PROCHOT
11: 0.24v - SDA
12: 0.30v - SCL
13: 0.04v - CMPIN
14: 1.20v - CMPOUT

15: 0.00v - BATPRES
16: 0.00v - TB_STAT
17: 1.24v - BATSRC
18: 1.15v - BATDRV
19: 1.25v - SRN
20: 1.24v - SRP
21: 0.06v - ILIM

22: 0.00v - GND
23: 0.15v - LODRV
24: 0.02v - REGN
25: 0.35v - BTST
26: 1.65v - HIDRV
27: 1.25v - PHASE
28: 19.5v - VCC

And photo for the internet techs;