Fe490/Fe590/FE480 NM-B911not charging

[Dinneke]

With battery it turns on but not charging through USB C.

Replaced U4201 RTS5455 because had a short.

[mon2]

Re: Fe490/Fe590/FE480 NM-B911not charging

Update - did replacing the PD controller fix your fault ?


Hi.

1) Do you have USB Type C meter ? They are very common on Aliexpress.

2 With the USB Type C meter in series between the external power adapter and this logic board -> power up.

What voltage & current does the Type C meter report as the power delivery contract ?

3) If you do not have the meter, it is still ok to use a normal multimeter in DC volts scale (30V or higher is suggested).

With the logic board on and external power supply connected, measure the voltage @ VSYSTEM2.

VSYSTEM2 is the power rail from the outside world that is powering this logic board. This rail must reach the right side of the charger circuit shown on page # 82 = B+ rail.

The battery mosfet is allowing for the battery to power the board.

4) What is the voltage at PQ101 pins 2-3-4-10 ? (with external adapter connected).

Next, power down -> remove the battery -> using only the external adapter and power up again. Measure this junction again and post the readings.

We want to know if the external power adapter is able to supply the charger IC with a voltage to power the logic board.

Does the logic board function WITHOUT the battery but with the external power adapter ?

Is the external adapter a known good source and suitable for this laptop use ?

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911not charging

Replacing PD controller did not solve the issue, not charging/no power

I do have a USB C meter, hows nothing not even a display.
Not powering at all with external power adaptor tryed original and
replacement.

PQ101 pins 2-3-4-10 measure 0V without battery.

VSYSTEM2 also 0V.

[mon2]

Re: Fe490/Fe590/FE480 NM-B911not charging

The USB Type C connector, as a minimum should show a +5v (default) power rail on VBUS pin.

See attached.

1) Is the external adapter a known good adapter and works with other widgets that use USB Type C ?

2) If yes, use your meter on another widget in your lab and confirm the meter can show you some readings like voltage and current consumption.

If it is a recent bidirectional USB Type C meter, it should.

I know we picked up on for under $10 USD from Aliexpress and it works ok to show most readings but not the super low current draw that our more expensive meter can show us.

However, the meter should light up and show you +5v or similar as a default.

3) Then, back to this board, remove all power from this non-working logic board -> meter in resistance mode -> check the resistance to ground of the VBUS connector. See attached.

What is the meter reading for the resistance ?

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911not charging

VBUS resistance is >200k.

External adapter and USB C meter works fine on smartphone(displays FAST/PD).

NOTE USB meter no display without device/load attached.

[mon2]

Re: Fe490/Fe590/FE480 NM-B911not charging

Does the meter on this logic board remain DARK with no display at all ?

Then you have a short between the connector and the PD controller.

The VBUS resistance is fine but you have some other fault on the connector.

Consider to remove all power -> meter in DIODE mode.

Red meter lead to ground (yes RED lead).

Black meter lead to a pin on the Type C connector pin. Check each and every pin on the Type C connector and post the readings for each pin.

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911not charging

Does the meter on this logic board remain DARK with no display at all ? YES

Testing in DIODE mode now.

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911not charging

A1 0v
a2 -
a3 -
a4 0.47
a5 0.62
a6 0.48
a7 0.48
a8 0.68
a9 0.47
a10 0.76
a11 0.76
a12 0v

b1 0v
b2 -
b3 -
b4 0.47
b5 0.62
b6 0.48
b7 0.48
b8 0.68
b9 0.47
b10 0.76
b11 0.76
b12 0v

[mon2]

Re: Fe490/Fe590/FE480 NM-B911not charging

See attached. While the Vbus rail appears to be ok and without a short, something downstream from this type C connector is causing the rail to tank.

Remove the highlighted parts and test again.

Does the USB C meter remain lit up without these series EMI ferrite bead inductors ?

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911not charging

yes, USB C meter shows 5V

Could it be faulty/short U4305?
Injection of 5-10V shows noting wrong with U4305

[mon2]

Re: Fe490/Fe590/FE480 NM-B911not charging

Good that the USB C meter is working.

See attached on the same U4305 LDO.

What is the resistance to ground for the output of this LDO ? (remove all power; meter in resistance mode)

When you injected 5-10v to the INPUT of this LDO, does the logic board boot normally ?

You have to be careful on the INPUT voltage as we do not know what is the max voltage for this Silergy part. So far, unable to locate a datasheet for this component. For this reason, keep the INPUT @ ~6V max and the buck LDO should spit out +5v if enabled.

Note that this LDO has an ENABLE function @ pin #1 to turn ON. The 100k on Vin should support this turn ON feature.

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911not charging

I assumed that the part is designed to take the max USB C output.

[mon2]

Re: Fe490/Fe590/FE480 NM-B911not charging

You have to be careful as USB C is available in many wonderful flavours. There is no guarantee that one USB C voltage is suitable for another device than it was designed for.

Every type C adapter will offer 5 volts as an output but the rest is upto the engineer who designed the product. They will then select an adapter with xx power delivery contracts (voltage & current pairs).

The PD contracts could be 1-2 or many and the max is upto the designer. 20V is a common choice and believe it is a max for one of the PD specs but higher voltages are also being used for next gen designs.

The PD controller will read out the contract table and select the best one for their use.

So it is possible that this product is made for 20V but best to confirm with the markings on the adapter or the datasheet for this product...

found this:

THINKPAD E590 AC Adapter, Canada 20V 3.25A

So no issue to use the power supply as you noted. This should allow for the LDO to operate @ 5v output.

Q: If you apply a 65W+ USB C power adapter -> does this logic board boot normally but just does not charge the battery ?

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911 not charging

20V is nominal for this board, i checked that before.

No power, no charge when i apply USB C power, no power/charge LED either.

5V LDO works normally.

[mon2]

Re: Fe490/Fe590/FE480 NM-B911not charging

Review this thread and use Google translate to English - same logic board; same fault with a fix:

https://www.xinxunwei.com/bjbwx/011610425.html

I believe the summary of this above thread is that the tech had better results to reach the 20v after using a cooler temp of 360 degrees on the hot air tool. With 380 degrees, the PD controller was damaged.

Do you have more of the Realtek PD controllers ? From assorted searches, the PD contract list is already pre-loaded inside this IC.

[Dinneke]

Re: Fe490/Fe590/FE480 NM-B911not charging

Thanks, I will look into that thread.

I had only one PD controller....order some more...