Troubles with HP pro x2 612 g2

[mon2]

Re: Troubles with HP pro x2 612 g2

No - this is only a USB hub controller. It fans a single USB port into multiple for your laptop.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

hidden under the small metal cover

[mon2]

Re: Troubles with HP pro x2 612 g2

From here:

https://support.hp.com/us-en/drivers...12-g2/14432855

it appears your controller onboard will be from CYPRESS.

then search for an IC with the following graphics on the topside:

https://www.bing.com/search?q=cypres...NTA1&PC=EDGEDB

See attached and it appears that there is a firmware tool / update to allow you to update the Cypress firmware. This is desirable to confirm you are current and that this tool can reflash the controller.

It cannot hurt to perform this update.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

[mon2]

Re: Troubles with HP pro x2 612 g2

That helps. See attached.

Cypress p/n CYPD4125 is the USB Type C controller for this logic board.

Does your power adapter power up this unit each & every time (without the battery connected) ?

The other chip, nearby is the TI 2546 which is a load switch - we can ignore this since your issue is with the main power source; not the downstream devices you may want to charge.

Datasheet for both are attached.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

yes every time
Oh the updated firmware was for docks only

Indeed I think this throubleshooting of the board will help many people, because there really nothing to be found elsewhere

[mon2]

Re: Troubles with HP pro x2 612 g2

See attached. With great care, review the voltage readings of the VBUS control pins.

That is, when the adapter is connected - these pins should offer some voltage to enable local mosfets (that should be nearby this controller IC).

These mosfets then feed to the charger IC.

If these mosfet driver pins are not enabling then the fault could be with the CC1 and CC2 pins on this IC.

To check the CCx pins; remove all power; meter in DIODE MODE.

Red probe to GROUND. Yes, RED probe.

Black probe to CC1 pin -> what is the reading ?

Repeat for CC2 pin -> what is the reading ?

Also - with no power -> meter in resistance mode -> do check the resistance to ground of any and all polarized caps nearby. Especially the tantalum in your posted picture. Tantalums are crap - we do not use them in any of our designs - with pride. Tantalums are cheap and are for planned obsolescence. When they die, they act like a short.

I am being pulled away - will continue to review over the weekend and post when I can. Review the above details and post your measurements.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

here are the readings
pin 7 0V
pin 9 0.67V
pin 11 0V
pin 12 4.75V
I don't think I have diode mode ou my tools

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

could it really be the charger ??

[mon2]

Re: Troubles with HP pro x2 612 g2

Post a pic of your meter.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

Oh wait, there s a diode mode...
I check the ic in the morning. Here in France it's 11:30 pm. Thank again. If we can figure out the problem I ll owe you a big one

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

hello.
I measured in diode mode the cypress ic pin 7 and 9
When red probe on ground, the black one read 0.53V on pin 7 and 9
I tried just in case to test with black on ground and red on pin 7 and 9, in that case pin 77 and pin 9 reads 0.77V
Now I try to check tantalum caps, but for me it's hard to recognize which one are concerned. I'll update what I manage to understand.

So there only so much polarized caps that I found. I believe they are always marked with a white stripe on positive, right ?

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

here I managed to take a photo trough my microscope. Is it normal that the cap pointed by the toothpick is grounded on both side ?

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

on a few post before you asked me to measure the cypress ic pin 7 9 11 12 when on charger.

I did it again, this time running on battery and plugging the charger after the board is powered on. In that case, reading are : pin 7 0V pin 9 0.7V pin 11 0V pin 12 0V
Though I'm still reading 5V on the two pin on the usb c port.

[mon2]

Re: Troubles with HP pro x2 612 g2

When you manage to glitch the external adapter to work, there is a 12v output from the power adapter.

This voltage is switched through mosfets before it reaches the battery charger IC mosfets.

Study the parts near this Cypress usb C controller to locate these other mosfets. These parts will be linked to the usb C Vbus line of the connector. We need to test these mosfets.

Post pics of other parts in this area. The mosfets will likely be 8 pins and similar to the other mosfets.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

When running on the charger alone, the two TCPA 8120 have 12V at Source, 12V at Drain, and 0.20V at gate. I checked their resistance : Infinite S to D, infinite G to D, 50KOms G to S

[mon2]

Re: Troubles with HP pro x2 612 g2

The parts are TPC8120. They are p-channel mosfets and look correct for the type C controller usage.

The voltages are correct to enable each mosfet.

When with the adapter alone, confirm the 12v presence on each boot..test a few times. This is important to confirm the power delivery contract is being negotiated.

After this confirmation, measure if the 12v reaches any of the pins of the battery charge mosfets. It should.

In this case, the logic board is not powered?

When you glitch the board to work, measure the same path of voltages. Do you still see 12v travel through these mosfets?

What is the gate voltage of these mosfets when working?

Have a concern of the low resistance being measured between gate and source. One of these mosfets may be leaking. The resistance should be much higher.

[johnjohnjohnjohn]

Re: Troubles with HP pro x2 612 g2

in fact, if the battery is not plugged in, the logic board turns on as soon as I plug the usb c charger. Everytime. Always 12V. I even used the pc like this a few hours. We could say it works normaly when battery is not plugged, though it display an error message every boot wrning me about the issue with the battery (bios think it s ether dead or missing, which is true. Same as if I use the pc on battery, i works fine, but in that case the usb c port seems deactivated. The type A is working fine.
The glich I found was that if I "hot plug", I mean I plug the battery on the logic board while the pc is already powered on with the usb c charger, then the battery charges. That's how I did to be able to use the battery alone.

[mon2]

Re: Troubles with HP pro x2 612 g2

Attach both, battery and charger.

Measure the voltage on these tpc8120 mosfets and also the charger 2 x DCin mosfets.

Post the readings.

[mon2]

Re: Troubles with HP pro x2 612 g2

Measure also the voltage on each pin of the battery connector.

The battery management system (BMS) is communicating with the charger IC over the smbus / I2C interface. Need to be sure the SCL and SDA pins are ok.