Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

[medinfo]

Lenovo L13
MB : LAR-1 MB 18834-1M

the computer starts normal with the battery, but does not start with the type-c charger, the usb type-c port only gives 5v not 20v .

[MOD EDIT] Link to schematic - https://www.badcaps.net/forum/showthread.php?t=125078

.

[mon2]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Do you have a USB Type C meter ?

Use it in series with the external adapter & this computer to confirm the current draw.

It is possible that the CC1 & CC2 lines are damaged from a hot adapter removal and cross shorts across the Type C contacts. Industry claims this very serious fault has been fixed with the wimpy BMC communication lines being tolerant to > 20V hits but do not know about this TI controller.

Start with removing all power.

Place your meter in diode mode.

Red meter (yes, red) lead on GROUND. Black meter lead on CC1 line. Diode reading?

Then repeat for CC2 line. Trying to determine if either one of these lines is damaged.

[medinfo]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

meter in diode mode
Red meter on GROUND and Black meter on CC1 USB2
Charger plugged in : Diode in meter = 680
Charger not plugged : Diode in meter = 612

[mon2]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Do not power up when testing with the DIODE mode.

Leave the charger removed.

Repeat the same test for CC2 line. Both, the CC1 and CC2 lines are used by the logic board & external power adapter to select the power delivery contract. The 5V contract is a power on default.

[medinfo]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

=470 in both CC1, CC2 !

[mon2]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Post the voltage for each of the pull-up resistors in the attachment.

Interested in the voltage on each of the '_I2C_' lines.

Update:

Also confirm the voltages on the Power Delivery Flash device. See attachment.

[mon2]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Can you also confirm if the CC1 & CC2 measurements were taken at the USB connector ?

That is:

USB2_CC1_CON
USB2_CC2_CON

[medinfo]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

sorry for the late reply and thank you for the interest in my problem.
this is the all mesurements .

[mon2]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Can you confirm that the type c charger is able to select 20v ?

Do you have any macbook units with type C?

Just to confirm that the adapter is not defective.

[mon2]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

For this design, U7301 is the decision maker for the power delivery contracts. This is an intelligent controller that communicates with the outside power adapter (type C) to request a catalog of power delivery contracts (voltage & current pairs). Then this component @ U7301 selects the best choice for the logic board (20v) to move forward.

Respectively, the communication is over the CC1 and CC2 lines.

You can try to flip the type C connector upside down and test again. Suggest to always, remove power on the type C adapter, seat the connector and then plug into the wall. This way, there is no 'hot' circuit on the adapters. Safer this way.

Do confirm that the type C contacts are CLEAN with alcohol & Q-tips. Have seen many burnt or liquid damaged contacts in our shop.

Next, between U7301 & the physical connector on the laptop is an ESD protection device @ U7503. It is very possible that this device is damaged and blocking the communication between the Type C controller (U7301) & the outside world (type C power adapter).

Check in diode mode, with all power removed, the readings of pins 11 & 12 on U7503.

Also, pins 4, 5, 6 and 7.

Check for any physical damage - clean up the solder contacts of any debris.

At this time, not sure if U7301 has factory firmware - most likely it will. It is a state machine device and will need some form of code to decide when to select which contract. TI should offer more details. Believe this is a public offering for this controller. If needed, we can post a request from the TI engineers in their user forum for more details about this laptop.

A very good tool here would be to have a USB Type C bus analyzer to study if there is any communication between the laptop & power adapter.

[Rotter]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Hi,
I just got this same notebook with the same problem on my workbench.
Only got 5V on the USB-C Connector.
there is no activity on the CC1 and CC2 pins.

replaced U7503 (CC Protection IC) -> no change

3D3V_LDO_PD is present.
3D3V_S5 is at 0V, which is guess could be normal in this state.

i see some periodic activity on the CS# bin of BIOS2 (EC7301) which i guess is the Firmware for the TPS65988DH (U7301).
I would like to reflash its rom, but could not find a dump anywhere, tried to find it inside the official bios update file from lenovo and inside the dump offered here.

Could somone please make a dump of this chip?

i will attach the one i read from my defective board,

Best regards.

[REpairAT]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Hi,
I just got this same notebook with the same problem on my workbench.
Only got 5V on the USB-C Connector.
there is no activity on the CC1 and CC2 pins.

replaced U7503 (CC Protection IC) -> no change

3D3V_LDO_PD is present.
3D3V_S5 is at 0V, which is guess could be normal in this state.

i see some periodic activity on the CS# bin of BIOS2 (EC7301) which i guess is the Firmware for the TPS65988DH (U7301).
I would like to reflash its rom, but could not find a dump anywhere, tried to find it inside the official bios update file from lenovo and inside the dump offered here.

Could somone please make a dump of this chip?

i will attach the one i read from my defective board,

Best regards.

Hi,
had the same notebook for repair with another issue, dumped the chip. I can't guarantee that this dump is fully functional, because the computer turned always off after few seconds, but voltage was always present.
Give it a try and let me know.
https://www.badcaps.net/forum/attach...5&d=1648656194

BR, Ray

[Naeem4rush]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Hi
i am in same problem but cc1 1.35v when i turn usb-c cable than cc2 is 1.35v
if any body know the problem ?

[Naeem4rush]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

REpairAT
you save the day your dump worked for me .

[Jasinka]

Re: Lenovo L13 (USB-C VIN ONLY 5V NOT 20V)

Hello,

i have same problem with L13 just 2th generation. Input with usb c is just 4.97v.

If i will use this custom bios it will help or i should change some parts? Thanks.
Found smth on youtube its says can be shorted with chipset...
Charging with second port - everything is fine.

Thanks for help in advance. i am noob here.