Troubles with HP pro x2 612 g2

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

could BQ24780S be damaged ?

[mon2]

Re: Troubles with HP pro x2 612 g2

Yes, it could be. They are very common parts.

https://www.aliexpress.com/item/3279...d=YBLXWO1IGF0t

https://www.aliexpress.com/item/3286...d=DNtp2BSGYHK4

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

so, i swapped it with two others I had on donor boards. Now 12V is allowed through the tpca8120 mosfets
Nothing more, though, still no power.
Just to check, I powered the board on battery with screen plugged in (tricky setup...) The board works like this, but when the battery will be empty, no way to charge it

[mon2]

Re: Troubles with HP pro x2 612 g2

Good to hear. Party @Piernov's will have to wait. I think the other mosfets linked to the 24780S will need a review when you are well rested. Good job on this fix to get here.

Need to check again,

ACDET
REGN
HIGH SIDE / LOW SIDE mosfets - are they shorted or not ? Their gate voltage ?
The current sense feedback from the coil that is charging the battery.
Battery mosfet as well.

Update:

Now use this state of the unit to download and reflash to the latest and greatest BIOS update. This procedure will also update the CYPD4125 firmware to be current. Curious to know if your charging of the battery state improves after this update.

Also - the thread linked earlier notes that similar faults were from the battery itself - what @Piernov has mentioned many times in his blogs. 99% of the time, the battery is at fault. Do you have access to this battery from Amazon ? Just for testing to rule it out before we dig deeper. With Amazon, you can always return the battery.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

0.22V at battery mosfet source, 0.25V at battery mosfet gate
0.22V at ACDET and REGN

11.8 0.14A on my power supply. the board blinks white orange a few times when I put on my power supply. It means it reacts which is good I guess.

While I was finishing this measure, suddenly the voltage dropped. Now, from the tpca 8120 drain pad where I soldered the wire to inject power, to the DC in mosfet drain : the resistance which was before 0, climb seemingly to the infinite.
Power supply showed me only 0.02 A so I cut it, that s how I saw the resistance building up

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

in fact, the resistance between dc usb c drain pad and the dc in mosfet now reaches 450 KOhms. I think the board gave up before I did. I believe resistance increasing suddenly between two pad means inside layer trace going bad

[mon2]

Re: Troubles with HP pro x2 612 g2

Earlier, you had success in powering up this board - was that with your power supply @ 12v ?

Now the logic board no longer powers up ?

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

nope ! even on battery. . .

Maybe it was too big of step to try such a tricky fix so early ?

[mon2]

Re: Troubles with HP pro x2 612 g2

Is your battery charged at this time ?

If it is, when you attach it to the logic board, do you see any voltage AFTER the 2 x DCin charger mosfets ? This is the common shared point where the Type C voltage enters the charger circuit to power the board OR the battery mosfet is enabled by the 24780S to use the battery to power the board.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

I see voltage until lowdrv drain.
And now It starts again, on battery. Unfortunately, now that there is huge resistance between tpca 8120 mosfet pad and E6 GUD...

[mon2]

Re: Troubles with HP pro x2 612 g2

And now It starts again, on battery.

Does this mean the unit is able to power up to install a new bios ?

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

In fact, I updated the BIOS first before even opening it up. It means the BIOS is the latest HP published for it

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

Hi,

I think I could try ordering the IC and mosfets on AliExpress. If it doesn't work, it will still be spare parts for another job, maybe.

The board forcing the manually chosen delivery contract, is it a way to bypass the cypress usb c controller when suspecting IC to adapter issues ? It might be useful, at least one day or another. What is it called ? I will order one.

I try to find a USB C port too.
If you think of anything that might be useful, please tell me, It will take at least two to three weeks until delivery, but I can't really blame the chinese, It's once in France that customs and postal service drag for at least a week.

[mon2]

Re: Troubles with HP pro x2 612 g2

Hi. Something like this:

US $0.72 33%OFF | PD/QC/AFC TYPE-C Fast Charge Trigger Polling Detector Notebook Power Supply Change Module Charger Board Tools 9/12/15/20V
https://a.aliexpress.com/_mqA21Kc

They are calling these 'decoy usb boards'.

Will post more suggestions tomorrow.