Thinkpad X280 working fine but not negotiatiating PD (stuck at 5v)->no battery charge/power-throttled performance

[ErParucca]

My apologies in advance if this has been discussed but doing a search for USB, PD, 5v, 20v etc leads to tons of results on unrelated topics.
Lenovo Thinkpad X280 working fine, 8250U, 16GB, no supervisor password, I would exclude BIOS/SW settings as this is evident even with the machine is turned off: If I measure the V/A between the laptop's USB-C port and the charger I see that this specific machine (I have another X280 to test with), does not negotiate 20v when the AC adapter is connected. Because of this:

• the machine is always (at boot and during windows normal operations) complaining of a low-wattage power supply
• battery charges extremely slowly (a bit less slowly if the system is powered off)

I assume this is not thinkpad-specific but more related to standard USB-C/Power Delivery standard ciruitry but I have no idea where to start with troubleshooting as my electronic skills are extremely basic. I wouldn't mind selling the parts except for the fact that this moBo is a 16GB one which are getting extremely rare.

Any advice on ow to troubleshoot? If I identify the component to replace I can have a shop to have it replaced for a decent price.

THank you!

[rumpumpel1]

The X280 has two USB-C ports. Do they both behave the same way?
Did you check this: https://www.badcaps.net/forum/troubl...olt-3-firmware

[mon2]

Are you using the original OEM power adapter for this unit? What is the power rating? The same power adapter works fine with your other X280?

USB-C ports are reversible. Flip the connector by 180 degrees and test in this orientation to see if the results are the same or different. The interface is very dainty and for this reason suggest to never plug in 'hot' when plugged into the wall socket. That is, plug the USB-C end first into the laptop and be sure it is securely seated and not at an angle - then plug the adapter into the wall. The USB-C port pins are wimpy in trace widths and cross-shorting is a real deal and can cause damage to the power delivery controller that is just after this USB-C connector.

Ideally, you can test the integrity of the USB-C port connections using the Qianli iBridge tool which will perform diode mode testing of each connection on the USB-C port. Then it will offer a pass / fail status.

[ErParucca]

The X280 has two USB-C ports. Do they both behave the same way?
Did you check this: https://www.badcaps.net/forum/troubl...olt-3-firmware

yes, they both act the same, forgot to mention it, thank for the reminder.

nothing to do with the thunderbolt 3 FW issue, thunderbolt is working fine.

Are you using the original OEM power adapter for this unit? What is the power rating? The same power adapter works fine with your other X280?

Multiple adapters that I use with other laptops (X13 Gen 2, X1 Carbon Gen 9, etc.) they all work fine on other laptops.

USB-C ports are reversible. Flip the connector by 180 degrees and test in this orientation to see if the results are the same or different.

I am no expert in electronics but have been working in IT for 30 years no changes.

I assume the ports (electrically) work fine as everything works (data, charge in, charge out) except for the fact that the negotiation from 5v to higher voltages is not happening.

Thank you everyone!

[rumpumpel1]

Some posts in this forum suggest that the Thunderbolt firmware issue is responsible for the 5V issue described.

[tomodachi]

My apologies in advance if this has been discussed but doing a search for USB, PD, 5v, 20v etc leads to tons of results on unrelated topics.
Lenovo Thinkpad X280 working fine, 8250U, 16GB, no supervisor password, I would exclude BIOS/SW settings as this is evident even with the machine is turned off: If I measure the V/A between the laptop's USB-C port and the charger I see that this specific machine (I have another X280 to test with), does not negotiate 20v when the AC adapter is connected. Because of this:

• the machine is always (at boot and during windows normal operations) complaining of a low-wattage power supply
• battery charges extremely slowly (a bit less slowly if the system is powered off)

I assume this is not thinkpad-specific but more related to standard USB-C/Power Delivery standard ciruitry but I have no idea where to start with troubleshooting as my electronic skills are extremely basic. I wouldn't mind selling the parts except for the fact that this moBo is a 16GB one which are getting extremely rare.

Any advice on ow to troubleshoot? If I identify the component to replace I can have a shop to have it replaced for a decent price.

THank you!

if you have two of these units and one of them is working, try swapping pd firmware chip (u184)

[ErParucca]

thanks everyone, it is indeed the TB FW issue. "Funny" thing being that I manually flashed the FW with a CH341A programmer and the laptop started negotiating 20v. Then after a while the problem cam back. Will try again and report back and eventually try to flash a copy of another system rather than the TBT.bin from the downloaded package as tomodachi suggested.

[ErParucca]

update: still working on it; remember seen it work once after update but not stuck back at starting point...

[ErParucca]

more and more weird: now I am able to get this:

but no way of detecting the TB controller or updating it.

[ErParucca]

leading to this:

I was also able to get the NV info to populate the bottom part of the panel but still impossible to update and USB-C stuck at 5v

[mon2]

Try a newer version of this tool from here:

https://support.lenovo.com/us/en/dow...type-20ke-20kf

[ErParucca]

thanks but that's exactly the one I used.

[mon2]

The version does not match the website details.

[ErParucca]

thanks but it seems to me the link you sent is for the thunderbolt firnware+update utility. The one you circled in red is the version of the thunderbolt software (something different).

[mon2]

https://www.reddit.com/r/thinkpad/co...lem_explained/

[ErParucca]

https://www.reddit.com/r/thinkpad/co...p_instruction/

if you like to play sharing links I've been through many different set of instructions but no one provide analytical troubleshooting guidance, just a bunch of things to try with no specific criteria. Some say to use specific versions, some, latest.

[mon2]

Have you tested the Linux approach?

[ErParucca]

yes but the controller is not visible so fwupdmgr doesn't list thunderbolt in the device list
I am confident I am doing something wrong because depending on the process I follow/FW used I can see the NV version in thunderbolt software (or not see it) so something changes. But to no extend as per the 5v negotiation/TB controller been visible to OS.

[mon2]

TBT controller (Alpine Ridge) is a PCIe device. Confirm the presence of the DC blocking caps on this device. If any of these caps are missing or are defective, then this PCIe device will not be enumerated and seen by the host.

[m1ch43lzm]

Schematics and boardview:
https://www.badcaps.net/forum/troubl...21-lenovo-x280
Find U184, backup it from the working X280 with an SPI flash programmer, and try flashing it to the non working one (make a backup first of course)
U184 is shared between Thunderbolt controller and USB-C PD controller

But if the problem is caused by excessive writes to the chip as suggested on the reddit post, program a new W25Q80DV or W25Q80JV chip with the contents of the one from the working laptop; you'll notice that the SPI flash chip is "worn out" if it fails to verify when programming
Run the Thunderbolt firmware update afterwards if it works (negotiates 20V)

https://support.lenovo.com/us/en/sol...dates-thinkpad

Symptom

Systems may experience any of the following symptoms:

• USB-C port not working
• Intel Thunderbolt controller not visible in the OS/Device Manager
• USB-C or Thunderbolt docking stations not visible or having connectivity problems
• HDMI output not available
• System battery not charging with a USB-C power adapter connected to the USB-C port
• Intel Thunderbolt pop-up error message
• Intel Thunderbolt safe mode error message
• BIOS Thunderbolt communication error or hang during POST

These symptoms may occur after 6 to 12 months of typical usage.