Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

[TranaRiparDis]

Hi everyone,

This is my second board level repair. My first one was on an Iphone 6 changing Usb controller 2 years. I didn't expect the phone to work again after the mess I did last time but it did and I was super proud. This time it seems more complicated.

When I first opened the laptop and plug it in I felt that the Cypd4226 (Usb type-c port controller) is getting hot so I remove it from the board and I found out that VCCD was shorted to GND on this chip so I ordered a new one but I didn't found the 4226 so I took the 4225. According to the datasheet they have the same pinout.





After soldering the new chip on the board, There was no more heat but the laptop didn't boot or charge. I took off the chip again and and took some measures. I found out that pin 23 on the board was shorted to GND.



I didn't found the schematic for this board for free so I bought it and share it with everyone on this forum.

I went through the schematic and found out that G517AL was shorted to GND so I took it off. I used the one of the port 1 because it is only the port 2 that boot and charge the laptop.





Unfortunately, the laptop still doesn't work. cypd4225 has 3v on VDDD but no power on Vconn_V5_P2, +5VDX_WALKPORT, +5VAUX. I read the datasheet of the cypd4225 and from what I understood there should be some sort of connection between cypd4335 and U17. When I mesure +3VALW_EC +3VALW_EC_A I only have 0.6V. Does anyone know how can I reestablish all the missing voltages or a proper way to debug this board ?

This USB C PD is so complicated I have spend the last 2 days trying to understand what is the problem I am afraid maybe this chip (cypd4225) need to be programmed.
Does anyone have experience USB C PD ? any help is appreciated.

[mon2]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Order the correct part Cypd4226 from a reputable vendor on AliExpress and test again.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Order the correct part Cypd4226

Going through the datasheet again I saw my mistake



This device need PD 3.0 not PD 2.0. Do you think I may created more damage by installing the Cypd4225 ?

CYPD4226 is not available at digikey or mouser. Do you know other than Aliexpress to buy this part? I don't want to wait a month for this part.

Thanks for your remark.

[mon2]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

The part is currently in stock @ Mouser (USA):

https://www.mouser.ca/ProductDetail/...-Semiconductor


Also available here in the USA:

https://www.questcomp.com/part/4/cyp...tandardpricing


I would order a few for inventory / spares.

On Aliexpress, you can also order the same part from reliable suppliers - check the reviews before proceeding but you are protected by the Aliexpress team. Have had to exercise their support only recently after hundreds of positive purchases. The vendor did not ship us the part after weeks and weeks of delays.

If you order from Aliexpress, you can select the slightly more expensive 15-20 days to USA / Canada which we use as a method of shipping. Best to use Mouser for this component as it is in stock.

On the PD 2.0 vs. PD 3.0, most likely PD3.0 is not really used as it is a relatively new spec. We did quite a bit of R&D with PD1.0 and it was a mess. Almost burnt my hands on a power delivery cable while docking with a Cypress development kit. Reported the issue to VIA Semiconductor for their USB cable controller. From my understanding, the issue should now be history.

The communication of the power contract occurs over the CC1/CC2 lines using biphase communications. If either is grounded, then this chat cannot occur. If you really are interested, there are some lower cost options to place a tool between the external Type C able and the target device so that you can monitor the power delivery contracts flying by in real-time. We have the Lecroy tool which is about $1k usd and does the same but ST offers some < $100 USD kits that can do sufficient monitoring of the same packet.

Suggest to just purchase the real and exact p/n from Mouser / Quest and replace on your logic board. Please keep this thread updated on your progress for future readers.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

I am still a newbie to USB C PD and I did some research about the suspect but I found it quit difficult after seeing the 600 pages of USB C specification document. But I understand some basics.


some notes I took about the topic back then

Before I order the cypd4226 from mouser, Do you think maybe Lenovo is running a custom code on this chip for their laptop? or it should work normally out of the box.

[mon2]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Hi. Good point. The micro is flash based and uses a supplied GUI tool to build proper the communication code with a wizard. Not sure if the code is protected as it has been a while since we worked with the Cypress devices and this one is more current than in our toolchest. If the code is not protected (quite possible) then using the SWD interface, you should be able to extract out the code from another working device.

Do you see more than one of these devices in your logic board?

Otherwise, a possible plan is to source a pre-flashed device from Asia if one exists or do the same from a donor logic board.

Otherwise, a new chip from any of the mainstream vendors will be blank.

Interesting reading:

https://community.cypress.com/t5/USB...20/td-p/119517

Which I am leading to believe that you may be ok here. That is, this component will be the I2C bus SLAVE for which there is an I2C bus MASTER who will then proceed to communicate with this device over this interface.

I think that it is worth an attempt. Please keep this thread updated with your progress.

According to this thread:

https://community.cypress.com/t5/USB...217945?start=0

Lenovo is able to supply you with the firmware for this component. Recommend that you contact Lenovo and explain your position so that they can share the proper firmware link for this repair. Then proceed to source the blank Cypress device from Mouser, etc.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Unfortunately, This is the only chip on the motherboard and it seems that this repair is not possible with a blank chip. Not sure if it is worth spending more money and time on this laptop. I will try to find a preflashed cypd4226 for this laptop if I don't find maybe I will try out a blank chip and share my experience.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

According to this thread:

https://community.cypress.com/t5/USB...217945?start=0

Lenovo is able to supply you with the firmware for this component. Recommend that you contact Lenovo and explain your position so that they can share the proper firmware link for this repair. Then proceed to source the blank Cypress device from Mouser, etc.

I tried to contact Lenovo today with chat and phone they were not helpful they said that my device is out of warranty so they can not help me. I asked a question on their forum for the firmware :

https://forums.lenovo.com/t5/Lenovo-...page=1#5299430

I don't expect they will answer me. This guy asked a similar question and no one answered him :

https://forums.lenovo.com/t5/Lenovo-...page=1#5299399

Interesting reading:

https://community.cypress.com/t5/USB...20/td-p/119517

Which I am leading to believe that you may be ok here. That is, this component will be the I2C bus SLAVE for which there is an I2C bus MASTER who will then proceed to communicate with this device over this interface.

It seems the cypd4226 comes preprogrammed from the factory. I will order 2 I hope lenovo uses the stock firmware.

[mon2]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Will see if we can get some answers from the Cypress forum. We have an account there. More details later.

PS: Hate the attitude that most manufacturers take of warranty period expiration, etc. Return the favor and don't buy their products. It will take them very little time of this outsourced tech support to investigate on how to apply fresh firmware onto this controller, if even required.

[mon2]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

FYI - Have posted on a new thread in the Cypress forum here:

https://community.cypress.com/t5/USB...30/td-p/272947

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Thank you very much for the help I appreciate it.


I received the part and soldered on board but the Vbus is still locked at 5V. I took some measures without the piece on board and there was 0V On Vbus. So I think there is communication between the charger and the chip on CC.
I asked a question on the Cypress Forum too about the firmware :

https://community.cypress.com/t5/USB...of/td-p/272812

I think now I must only flash Lenovo Firmware for this device. I am going to try to find someone who have it like the schematic and the board view.

Lenovo released the firmware for this chip for the yoga 920 only as an exe file after some customers had problem connecting hdmi monitor through USB type C :
https://pcsupport.lenovo.com/us/en/p...20-13ikb-glass

Someone already installed this one for c930 and he's laptop stopped charging or booting after that :
https://forums.lenovo.com/t5/Lenovo-...page=1#5299399

Does anyone know if I flash the bios again maybe the EC will flash FW for this chip too?

The battery now is showing 0V I think there is a protection circuit on the battery that is locking the voltage. I have to find a way to bypass this circuit so I can charge the battery using my Imax b6 charger. After that I can turn on the device again to download and flash the bios as exe file.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Lenovo forum is suggesting to install Thunderbolt Drivers :

https://forums.lenovo.com/t5/Lenovo-...page=1#5299933

I don't think intel Drivers will be enough.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Force charging 😈



of couse not sleeping and leaving this on

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

I charged the battery and I was expecting the PC to turn on but it seems there is another problem.

The power Led is blinking 3 times. Do Anyone know what does that mean ?

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

How do I know when it is a bios problem ?

[jimanez11]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

Have this board as well and am not receiving any signs of life from the board - but am happy to help pull the firmware from the cypd4226 chip (assuming mines not toast) if you can provide me with some guidance on how I could accomplish this. Am here for learning and this would be helpful for the both of us.

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

I never done this before but from the research i made you need to have PSoC programmer

[TranaRiparDis]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

According to this thread on cypress forum :
https://community.cypress.com/t5/PSo...ice/m-p/211409

it is possible de to relative the firmware as text data. Do you know if text data can be useful?

[jimanez11]

Re: Lenovo yoga c930 NM-B741 Doesn't boot or charge USB type-C controller issue.

I have a fairly inexpensive TL866II Plus programmer that i used to program a few pics, but this does support eeprom and mcu as well - would this work as a PSoC alternative? Im fairly new to the majority of this - only got the programmer so I could build a telescope tracking system. Otherwise, i am happy to do some research on this over the next few days - will also have to grab this board and put it near the top of the "to-do" list. Let me know if you have any suggestions or if you think a text dump would work for this. If its worth trying, im happy to give it a whirl.