820-02020 no touch bar

[Sr. Robot]

Hi, got a 820-02020 board with no touchbar (no light no touch).

Tried known working palmrest, no change.
Updated to Sonoma from Ventura, no change.

If i change touchbar configuration in OS then the touchbar lights up, but touch still doesnt work.

Measured diode mode on both JT710 and JT700 (dont have good board to compare)

The only pin i found suspicious was DFR_1V8_TOUCH_CLK32K_RESET_L (measured 0.700 on diode mode)

Both RT857 and RT801 resistances measure good.

I get every votalge on UT820 but DFR_TOUCH_CLK32K_RESET_L and DFR_1V8_TOUCH_CLK32K_RESET_R_L

DFR_TOUCH_CLK32K_RESET_L starts on 0.6v and goes to 0v in about 5secs, loops once and then stays on 0v.

DFR_1V8_TOUCH_CLK32K_RESET_R_L does the same but with 0.9v

 

[Sr. Robot]

Also tried DFU

 

[2informaticos]

Did you try known good touchbar?
ALS works correctly?

 

[Sr. Robot]

Yes. Tried good touchbar.

ALS works

 

[2informaticos]

Tried DFU restore, or just revive?

 

[Sr. Robot]

I did a restore

 

[2informaticos]

Check DFR_LID_OPEN_L.

 

[Sr. Robot]

i get 1.8v on DFR_LID_OPEN_L

 

[2informaticos]

Compare diode mode readings on touchbar connectors with good board.

 

[Sr. Robot]

JT700		Bad Board	Good Board
1	1 TP_DFR_TOUCH_PANEL_DETECT:	.0l	.0l
2	2 DFR_LID_OPEN_L:	.0l	.0l
3	3 DFR_DISP_VSYNC:	.0l	.0l
4	4 TP_DFR_TOUCH_RSVD:	.0l	.0l
7	7 SPI_1V8_DFR_MISO:	.455	.482
8	8 SPI_1V8_DFR_CS_L:	.386	.395
9	9 SPI_1V8_DFR_CLK:	.405	.399
10	10 SPI_1V8_DFR_MOSI:	.404	.397
13	13 DFR_1V8_TOUCH_INT_L:	.726	.478
14	14 I2C_DFR_RES_SCL:	.512	.318
15	15 DFR_1V8_TOUCH_CLK32K_RESET_L:	.397	.408
16	16 I2C_DFR_RES_SDA:	.520	.318
18	18 DFR_1V8_TOUCH_RESET_L:	.535	.316
19	19 TP_DFR_TOUCH_ROM_WC:	.0l	.0l
20	20 PP1V8_AWAKE_DFR:	.370	.375
21	21 PP1V8_AWAKE_DFR:	.375	3.75
22	22 PP5V_S2_DFR_FILT:	.250	.254
JT710		Bad Board	Good Board
3	MIPI_DFR_CLK_CONN_FILT_P:	.295	.314
4	DFR_DISP_VSYNC:	.0l	.0l
5	MIPI_DFR_CLK_CONN_FILT_N:	.296	.314
6	DFR_1V8_DISP_TE:	.723	.479
9	MIPI_DFR_DATA_CONN_FILT_P:	.295	.312
10	DFR_1V8_DISP_INT:	.528	.315
11	MIPI_DFR_DATA_CONN_FILT_N:	2.97	3.13
12	DFR_1V8_DISP_RESET_L:	.513	.316
15	PP1V8_AWAKE_DFR:	.375	.377
17	PP1V8_AWAKE_DFR:	.375	.377
18	PP3V3_AWAKE_DFR:	.503	.503
20	PP3V3_AWAKE_DFR:	.503	.504
21	I2C_DFR_RES_SCL:	.514	.318
22	PP3V3_AWAKE_DFR:	.503	.504
23	I2C_DFR_RES_SDA:	.313	0.318

 

[2informaticos]

Recheck SPI_1V8_DFR_CLK, DFR_1V8_TOUCH_INT_L and DFR_1V8_DISP_TE.

 

[Sr. Robot]

I had a typo in SPI_1V8_DFR_CLK value on good board.

DFR_1V8_TOUCH_INT_L and DFR_1V8_DISP_TE still .720

 

[2informaticos]

High readings may denote connection problems with M1 CPU.
Or even internal CPU issue...

 

[Sr. Robot]

Im comparing values with this page:

OpenBoardData Project

and they get similar values for DFR_1V8_TOUCH_INT_L and DFR_1V8_DISP_TE, so i dont get why im getting them lower on the good board.

Im still getting 1.8v on DFR_1V8_TOUCH_INT and 0v on DFR_1V8_DISP_TE (both same as good board)

 

[2informaticos]

The RESET_L signals must go high on both connectors.
And is not your case; should find why.

 

[Sr. Robot]

DFR_1V8_TOUCH_CLK32K_RESET_L stays at 0.9 for about 5 secs then goes off.

DFR_1V8_TOUCH_RESET_L shows up at 1.8v for a sec then goes off.

DFR_1V8_DISP_RESET_L stays at 1.8v

I get the exact same behavior on the good board.

 

[haimac]

DFR_1V8_TOUCH_CLK32K_RESET_L stays at 0.9 for about 5 secs then goes off.

DFR_1V8_TOUCH_RESET_L shows up at 1.8v for a sec then goes off.

DFR_1V8_DISP_RESET_L stays at 1.8v

I get the exact same behavior on the good board.

I have the same problem, did you solved it?