Hello All,
This is a weird one. This M1 Macbook Pro was brought in for liquid damage. Customer was getting video only on external monitor. Most liquid damage was located around the backlight circuitry, namely the backlight capacitor bank. It was not too severe. Ultrasonic cleaned and about 3 corroded capacitors replaced. FP800 backlight fuse was also blown. Nothing down the line from the fuse is shorted. May have blown this fuse from overload during liquid being present.
Also had to repair area of QD530 which is PBUS VOLTAGE SENSE. Repaired traces to RD531 and RD532 as well as replaced the resistors themselves. Also repaired trace for PIN 3 of this QD530 to pad of NO STUFF RD530. Voltages around the IC now measure as follows.
1. 0
2. 1.71V
3. 12.01V
4. 12.01V
5. 7.35
6. 0V
Unfortunately I seem to still be at the same place the computer was when it was brought in. Turns on, chimes, displays on external monitor. However the following is missing or having issues:
There is no display and no backlight. Backlight circuitry not producing backlight voltage.
JP600
4 EDP_PANEL_1V8_EN 1.07
43 PPVOUT_LCDBKLT 0V
44 PP3V3_SW_LCD_CONN 3.3V
45 PP5V_SW_LCD_CONN 5.V
46 PP5V_CAM 5.0V
There is no trackpad. It does not click. I checked support voltages and they are present. I did not have enable voltage at pin 17 presumably since I had to disconnect flex cable to take measurements at the connector.
JT400
1 IPD_LID_OPEN_1V8 1.8V
17 SPI_TPAD_EN_CONN 0V
21 PP5V_S2_TPAD_CONN 5.01V
25 PP1V85_S2_TPAD_ISNS 1.82V
29 PP3V3_S2_TPAD_ISNS 3.3V
There is also no keyboard activity though it is hard to tell for sure as I can only see login screen on my external monitor if I close the lid. I assume keyboard is not there since I can't boot into hardware test nor boot option menu.
JT200
1 PP1V85_S2_KBD_ISNS 1.84V
27 PP3V3_AON_KBD_CONN 3.28V
There is also no USB activity. I am using a USB-C adapter to view on external monitor via HDMI. Though HDMI and charging works fine, if I hook up a mouse or keyboard through my USB-C adapter the lights on either the keyboard or mouse do not light up. It is as if there is no USB activity.
Fan is spinning full speed. I recognize this as a symptom from where there is no TPAD connected.
Voltages around U7700 are fine.
Voltages around U8100 also seem fine when compared to wiki article except for
PCPU 0.61, article says 1.06B
ECPU 0.61, article says 1.06V
PPVDD_SOC_S1 0.68, article says 0.85V.
I am however not sure if this is an issue or not as I found another forum post somewhere and the person's board measured 0.61V as well on the first two measurements. Unsure about what the usual measurement is for PPVDD_SOC.
I am trying to figure out what the commonly shared issue to no avail. Your help would be greatly appreciated.
This is a weird one. This M1 Macbook Pro was brought in for liquid damage. Customer was getting video only on external monitor. Most liquid damage was located around the backlight circuitry, namely the backlight capacitor bank. It was not too severe. Ultrasonic cleaned and about 3 corroded capacitors replaced. FP800 backlight fuse was also blown. Nothing down the line from the fuse is shorted. May have blown this fuse from overload during liquid being present.
Also had to repair area of QD530 which is PBUS VOLTAGE SENSE. Repaired traces to RD531 and RD532 as well as replaced the resistors themselves. Also repaired trace for PIN 3 of this QD530 to pad of NO STUFF RD530. Voltages around the IC now measure as follows.
1. 0
2. 1.71V
3. 12.01V
4. 12.01V
5. 7.35
6. 0V
Unfortunately I seem to still be at the same place the computer was when it was brought in. Turns on, chimes, displays on external monitor. However the following is missing or having issues:
There is no display and no backlight. Backlight circuitry not producing backlight voltage.
JP600
4 EDP_PANEL_1V8_EN 1.07
43 PPVOUT_LCDBKLT 0V
44 PP3V3_SW_LCD_CONN 3.3V
45 PP5V_SW_LCD_CONN 5.V
46 PP5V_CAM 5.0V
There is no trackpad. It does not click. I checked support voltages and they are present. I did not have enable voltage at pin 17 presumably since I had to disconnect flex cable to take measurements at the connector.
JT400
1 IPD_LID_OPEN_1V8 1.8V
17 SPI_TPAD_EN_CONN 0V
21 PP5V_S2_TPAD_CONN 5.01V
25 PP1V85_S2_TPAD_ISNS 1.82V
29 PP3V3_S2_TPAD_ISNS 3.3V
There is also no keyboard activity though it is hard to tell for sure as I can only see login screen on my external monitor if I close the lid. I assume keyboard is not there since I can't boot into hardware test nor boot option menu.
JT200
1 PP1V85_S2_KBD_ISNS 1.84V
27 PP3V3_AON_KBD_CONN 3.28V
There is also no USB activity. I am using a USB-C adapter to view on external monitor via HDMI. Though HDMI and charging works fine, if I hook up a mouse or keyboard through my USB-C adapter the lights on either the keyboard or mouse do not light up. It is as if there is no USB activity.
Fan is spinning full speed. I recognize this as a symptom from where there is no TPAD connected.
Voltages around U7700 are fine.
Voltages around U8100 also seem fine when compared to wiki article except for
PCPU 0.61, article says 1.06B
ECPU 0.61, article says 1.06V
PPVDD_SOC_S1 0.68, article says 0.85V.
I am however not sure if this is an issue or not as I found another forum post somewhere and the person's board measured 0.61V as well on the first two measurements. Unsure about what the usual measurement is for PPVDD_SOC.
I am trying to figure out what the commonly shared issue to no avail. Your help would be greatly appreciated.
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