Lenovo NM-B501 mainboard Type C charging stuck at 5V

[vexarvf1s]

Looking for help.
I have a Lenovo ET480 NM-B501 mainboard that I needed to replace the usb-C port on.
After changing the port the computer works, but the DC-in from the type C power cord never goes above 5V.
I took pictures before replacing the USB port on the mainboard and I am not seeing any componets missing.

[vexarvf1s]

Re: Lenovo Type C charging stuck at 5V

Using the following schematics to track down my problem:

LENOVO THINKPAD T480 shematics

https://www.badcaps.net/forum/showpo...88&postcount=3

[vexarvf1s]

Re: Lenovo Type C charging stuck at 5V

I am looking at the PD Controller chip as I am noticing USBC_VBUS20 and TBT_VBUS20 go to this chip.
Below are the voltages I mesured.
Does anyone know if these voltages look ok?

PD Conntroller
SN1701012RJTR (TPS65988)

01 PP_HV2 5.1V
02 __|
03 VBUS2_ 4.88V/-1.7mv depending on port power is plugged into
04 __|
05 VIN_3V3 3.35V
06 ADCIN1 3.016V
07 LDO_3V3 3.32V
08 ADCIN2 3.016V
09 PP_HV1 5.12V
10 __|
11 VBUS1 -1.7mv/4.88V depending on port power is plugged into
12 __|

13 GPIO0
14 GPIO1
15 GPIO2
16 GPIO5
17 GPIO6
18 GPIO7
19 C1_CC1
20 PP1_CABLE 5.12V VCC5M
21 C1_CC2 1.3mV
22 I2C1_SCL 3.3V
23 I2C1_SDA 3.2V
24 I2C1_IRQ# 0

25 HPD2/GPIO3
26 HPD2/GPIO4
27 I2C2_SCL 3.29V
28 I2C2_SDA 3.29V
29 I2C2_IRQ# 3.29V
30 LDO_1V8 1.79V VCC3_LDO_TBT_R
31 SPI_MISO/GPIO8 3.3V
32 SPI_MOSI/GPIO9 0
33 SPI_CLK/GPIO10 0
34 SPI_SS#/GPIO11 3.3V
35 GPIO12 0
36 GPIO13 -1.4mV

37 GPIO14/PWM1 0
38 GPIO15/PWM2 0
39 HRRESET Ground
40 CS_CC1 mV
41 PP2_CABLE 5.12V VCC5M
42 CS_CC2 1.65V
43 PP_EXT1/GPIO16 0V
44 PP_EXT2/GPIO17 3.32V
45 C1_USB_P/GPIO18 -1.4mV
46 C1_USB_N/GPIO19 -1.4mV
47 C2_USB_P/GPIO20 -1.4mV
48 C2_USB_N/GPIO21 -1.4mV

[tomodachi]

Re: Lenovo Type C charging stuck at 5V

Sounds like a typical Thunderbolt issue. Find U15 and flash it with attached .bin file and try.
Remember to make backup first.

[SMDFlea]

Re: Lenovo Type C charging stuck at 5V

Sounds like a typical Thunderbolt issue. Find U15 and flash it with attached .bin file and try.
Remember to make backup first.

Please post your dumps in a new thread or this one in the bios requests section -> https://www.badcaps.net/forum/showthread.php?t=82558 .Then,post a link to it.

.

[vexarvf1s]

Re: Lenovo Type C charging stuck at 5V

SOLVED:

Sounds like a typical Thunderbolt issue. Find U15 and flash it with attached .bin file and try.
Remember to make backup first.

Thank you very much for pointing me in the right direction tomodachi.
Some legs of U15 had broken solder connections to the board.
Reflowed the Winbond chip and the USB charging ports both work as expected.

[tomodachi]

Re: Lenovo Type C charging stuck at 5V

SOLVED:



Thank you very much for pointing me in the right direction tomodachi.
Some legs of U15 had broken solder connections to the board.
Reflowed the Winbond chip and the USB charging ports both work as expected.

I m glad you solved it

[t34v2]

Re: Lenovo NM-B501 mainboard Type C charging stuck at 5V

God bless you for this thread. I had same problem and i've spent few hours to figure out what is wrong. This thread nailed it. Thanks!

[rbvndonh]

I correct solder joints and measured resistance to ground. It was same as other board with working 20V.
i dumped from OK board U15 chip and just reflash it to old board. Verification was OK, but board was still not working.
I tried to read dump to compare and it give errors during verify.
After soldering new W25Q80BV all went well and i have 20V 😀