HP 450 G3 - No power

[krayz]

Laptop: HP 450 G3
Motherboard: DAX63CMB6C0 REV: C
History: Stopped working after a power surge (supposedly through the RJ45 port)
Issue: Does not respond to power button (power LED is on though)
What I've done/checked so far:
-Visual inspection: Board looks fine, even under scope
-Charging port and cable ok. Charging port is also ok
-Removed battery and reset CMOS
-Measured 19v rail - passes the first two mosfets only.
-Measured all the coils: only 5V present.

Fixing it is not top priority, learning is (would be nice if I could find the fault). I have the boardview file and schematics. Help appreciated.

[krayz]

Re: HP 450 G3 - No power

Boardview ---> https://www.badcaps.net/forum/showth...641#post984641
Schematic ---> https://www.badcaps.net/forum/showth...096#post975096

[Sephir0th]

Re: HP 450 G3 - No power

Main power rail and LDOs are working. Do you have a unexpected low ohms reading at one the big inductors?

[Vesko356]

Re: HP 450 G3 - No power

Boardview...

Do not attach schematics/boardviews in this section please!

Schematic Requests ONLY!
https://www.badcaps.net/forum/forumdisplay.php?f=41

Reminder: rules and organization of this section
https://www.badcaps.net/forum/showthread.php?t=117483

If you request/offer BIOS/schematics/boardviews, please post in the appropriate subsection, and you can link to it in the troubleshooting topic.

.

[krayz]

Re: HP 450 G3 - No power

Sorry about that.

Main power rail and LDOs are working. Do you have a unexpected low ohms reading at one the big inductors?

Yep, 7-8 ohms on the big ones.

[mcplslg123]

Re: HP 450 G3 - No power

Sorry about that.



Yep, 7-8 ohms on the big ones.

This doesnt makes sense as you have not mentioned the coil numbers along with readings for resistance to GND.

[krayz]

Re: HP 450 G3 - No power

Here is a picture of the board with more details on the resistances.

[Sephir0th]

Re: HP 450 G3 - No power

This smells pretty much like a shorted PCH. I don't have access to the schematics and boardview right now, but if someone can confirm the "0 Ohms" coils belong to 3.3V and 1.05V then it is very likely a dead end here.

[krayz]

Re: HP 450 G3 - No power

Well that sucks. Any way to confirm it for certain?