MacBook Air M2 A2681 no Trackpad

[rynr]

Hello,
I have been following the posts in the forum for some time now and have learned a lot. I would first like to thank you for this and hope that it will continue for a long time.

I received the MacBook in DFU. The recovery always failed with error 1. After some search, I was able to find a defective inductor (LT202).
After replacing the component, I was able to successfully complete the DFU restore. Unfortunately, the trackpad and keyboard where still without function.

So i measured all voltages and diodereadings on the JT400 connector.

JT400
41 GND	d 0	42 GND	d 0
1 I2C_SMC_IPD_SCL_CONN	v 3.2	2 SPI_IPD_MOSI_CONN	v 3.2
3 I2C_SMC_IPD_SDA_CONN	v 3.2	4 SPI_IPD_MCU_CS_CONN_L	v 3.2
5 I2C_KBD_SCL	v 3.2	6 SPI_IPD_MISO_CONN	d 0.432
7 GND	d 0	8 IPD_SYS_AWAKE_CONN	v 0.086 → 3.2
9 I2C_KBD_SDA	v 3.2	10 GND	d 0
11 KBD_INT_L	v 3.2	12 SPI_IPD_CLK_CONN	d 0.438
13 IPD_TOUCH_CLK_CONN	d 0	14 IPD_MCU_RESET_CONN_L	v 3.2
15 SPI_IPD_TOUCH_CS_CONN_L	v 3.2	16 IPD_TOUCH_RESET_CONN_L	v 3.2
17 GND	d 0	18 SWD_IPD_DATA_CONN	OL
19 IPD_TOUCH_INT_CONN_L	v 3.2	20 SWD_IPD_CLK_CONN	OL
21 IPD_LID_OPEN_1V8	v 1.7	22 IPD_MTP_FUNC_1_CONN	d 0.513; v 3.2
23 TPAD_KBD_WAKE_CONN_L	v 3.2	24 GND	d 0
25 IPD_MCU_INT_CONN_L	v 3.2	26 PP3V3_S2SW_IPD_F	v 3.2
27 GND	d 0	28 PP3V3_S2SW_IPD_F	v 3.2
29 PP5V_S2_IPD_F	v 5.1	30 PP3V3_S2SW_IPD_F	v 3.2
31 PPBUS_AONSW_IPD_F	v 12	32 PPBUS_AONSW_IPD_F	v 12
33 PPBUS_AONSW_IPD_F	v 12	34 PPBUS_AONSW_IPD_F	v 12
35 PPBUS_AONSW_IPD_F	v 12	36 PPBUS_AONSW_IPD_F	v 12
37 PPBUS_AONSW_IPD_F	v 12	38 PPBUS_AONSW_IPD_F	v 12
39 PPBUS_AONSW_IPD_F	v 12	40 PPBUS_AONSW_IPD_F	v 12
43 ACT_GND	d 0	44 ACT_GND	d 0

Pin 8 only had a voltage of 0.086 V. After replacing UT360, the voltage is now 3.2 V.

Now when the old trackpad is connected, the keyboard works. However, the trackpad has no function.
Neither can the mouse pointer be moved nor can the pad be clicked. If I connect a replacement trackpad, the keyboard also has no function.
I have also tested two different connection cables. Both with the same result.

Does anyone have any idea what I could check next?

[mon2]

Review the cables linked to each component. Any sharp bends in the cable? May mean that conductor is defective.

https://boards.rossmanngroup.com/thr...sue-lid.64702/

[rynr]

Hi mon2,

thanks for the reply.

Review the cables linked to each component. Any sharp bends in the cable? May mean that conductor is defective.

https://boards.rossmanngroup.com/thr...sue-lid.64702/

You mean connector, right?

[mon2]

Cables as well. Often they are the first defect. Be sure also of the # of contacts on the cables being deployed. Does the pin-pin pitch of each contact match the mating connectors? Have done this here and installed a similar width TP cable but the total # of contacts were different than the OEM. Wasted time on that one. Best to count the # of contacts under a good microscope. Be sure the orientation (bottom side / top side - check which is proper for your model - YT is good for this) of the cable is correct and well inserted inside the blade connectors.

[rynr]

Hi mon2,

thank you for the reply. Yesterday a donor board arrived and I could test. The trackpad is working fine with this board.
In system preferences and in settings tab the trackpad and keyboard are shown..



But on the other board it is not listed.



Also, I found that SPI_IPD_MOSI_R, SPI_IPD_CLK_R & SPI_IPD_MISO on the working board have low voltages. But on the defective one I'm measuring 0.
For me it seems as the SPI communication isn't enabled. Or could this part of the CPU be defective?

[mon2]

Review the details of the level shifter used by the trackpad interface @ UT360. This part may be defective if you are measuring 0v on each SPI pin.

[vins3433]

Hi everyone,

I'm experiencing the same issue as described in this thread with a MacBook Air M2 (A2681) – the trackpad is completely non-functional, while the keyboard works fine.

I have already performed several checks:

• Replaced UT360 (SPI Level Shifter) – no change.
• Checked trackpad power lines – all voltages seem correct.
• SPI lines analysis (MOSI is active, but MISO and CLK remain at 0V).
• SMC reset performed – no effect.
• Checked continuity of SPI lines between UT360 and the trackpad connector – all connections seem fine.
• Tried another trackpad – same result.

I was wondering if you managed to find a solution to your issue, or if anyone on the forum has additional troubleshooting ideas.

Thanks in advance for your help!

[mon2]

Confirm the VCCA and VCCB power rails on the SPI level shifter.

Confirm the resistance to ground of MISO and CLK of the SPI lines. You may also do the same in diode mode (red meter probe to ground; black meter probe to point to test; no power to the board).

[vins3433]

Hi,

Thanks for your reply! I've taken all the measurements you asked for (Voltage, Resistance, and Diode Mode) on the UT360-related lines. To make it easier, I've attached three screenshots with all the values clearly marked. Repair History & Issue Background:


This MacBook Air M2 originally came in for a screen replacement at another repair shop.

• The screen was broken, and they attempted to replace it.
• However, after the screen replacement, both the keyboard and trackpad stopped working.
• The customer canceled the repair, asked them to put the original broken screen back, and took the laptop.
• When I received the device, it still had a broken screen, and neither the keyboard nor the trackpad were working.

What I've Done So Far:

1. Found a short circuit on UT360 → I replaced UT360, but the keyboard and trackpad were still not working.
2. Found another short circuit on UT320 → I replaced UT320, and the keyboard started working again, but the trackpad still does not work.
3. Bought a brand new trackpad with a new trackpad flex cable → Same issue.
4. Swapped the cables between the old and new trackpad → Same result.

At this point, the keyboard is fully functional, but the trackpad remains unresponsive.

I've attached the requested measurements. Let me know if you have any further suggestions or tests I should perform.

Thanks again for your help!

[mon2]

How are you observing the details? Using an external monitor over HDMI?

Post clear pics of the replaced level shifter parts region for a review. The cables are firmly seated inside the FFC/FPC connectors? Deep enough that they are mating with the contacts?

In the inventory screens, is it the MT-version that is missing from your reworked board = trackpad? Personally have not reviewed this screen in the past.

[vins3433]

Hi,

Screen replacement – I'm using a brand-new screen now, so I can see everything clearly. The original broken screen was still working (except for the bottom part), but I tested with it again, and same issue. So, the screen isn't the problem.

MT version missing – I checked System Information, and the trackpad isn't detected. I've attached a screenshot.

Photos of UT360 & UT320 – Here are the pics of the replaced components, let me know if anything looks off.

Cables – Double-checked, they're fully seated and properly inserted.

UT320 replacements – I've actually replaced UT320 three times already:

• First, I ordered the same part from AliExpress and replaced it.
• Since that didn't work, I took the equivalent component from a 2018 MacBook Air board and swapped it in.
• Later, I replaced it again with a new one from AliExpress, just to be sure.
• The keyboard started working again after replacing UT320, but the trackpad is still dead.

Next step: replacing UT350 – I read on other forums that a short on UT360 can also damage UT320 and UT350. My measurements on UT350 show that it's working fine, but I'll probably replace it anyway, just in case. I don't expect this to fix the issue, but I'll do it as a precaution.

Let me know if you have any other ideas. Thanks!

[rivskiano1]

https://www.bilibili.com/video/BV1VV...4f287d2cb5c94f

Hello, maybe that's would be helpfull

[Lloydz]

Hi, just would like to thank you for the information, just had a A2681 with the same anomaly. UT350 was sending 3.25V, but was causing anomalies with the trackpad, after replacement trackpad has worked OK.
BTW PP3V3_S2SW_IPD should have about 7kohm. thats how I found the culprit.