This is a mid 2019 Macbook Pro touchbar model. Motherboard is 820-01598. Technical information is going to be attached below including power sequencing graph.
I am having the issue of no 20V on the USB C port. USB-C Stays at 5V permanently. Current draw is 130mA. If I connect and disconnect in a certain way I can sometimes obtain a 300mA draw.
This laptop came in for water damage and although there was some corrosion it was not very bad. The board was ultrasonic cleaned but is not powering on. Laptop was having 20V prior to cleaning but there was no signs of charge or power with 0 or near 0A draw. Now there is only 5V 130mA draw.
Most of the corrosion found was around U8510 where it was cleaned and nothing too detrimental was found. This IC seems in charge of turning on the display panel and should not have much to do with our USB C issue. The worst of the corrosion was here and the biggest victim was a large capacitor where one end was completely eaten away. All traces and BGA balls look fine after cleaning and component replacements. This circuit is found next to LCD display connector though this connector itself does not show corrosion.
Some corrosion was found around one CD3127 chip but was fairly light and was easily cleaned. Chip was re-flowed with no luck.
A bit more corrosion was found on the bottom side of the board where U7800 is located. This corrosion was also light and the capacitors affected were only lightly corroded and could be re-tinned. No shorts found among these capacitors.
There was a bit more corrosion around U6903 which seems in charge of producing PP3V3_G3H RTC which was cleaned up and is working fine. Corrosion here was also fairly light.
Among the anomalies found are:
A bit of heat coming from the T2 chip while the USB C charger is plugged in and drawing 130mA. Same goes for when I can get the machine to draw 300 by quickly disconnecting and re-connecting the USB C ports. Behavior is the same on both ports. Heat on T2 is fairly light, warm at best.
The 5V LDO on U7650 was not functioning and was at complete zero though no short was detected. This chip produces PP5V_G3S and PP3V3_G3H. Out of the two PP5V_G3S is missing. PP3V3_G3H is present. Upon replacement of this chip 5V LDO partially returned at 2.75V. A second chip was installed and LDO still stays at 2.75V. No obvious short can be found on line. The filter capacitor immediately at the output of this LDO line was replaced with no luck. This does not seem to be connected to anything.
Enable signal for PP5V_G3S is missing.
LDO voltages at CD3217 chips are present and there are no obvious shorts around these two chips.
Using the power sequencing graph attached below the following voltage measurements were observed. Measurement list is up until the segment where I found issues.
VALID EXTERNAL POWER SOURCE, BATTERY OR CHARGER >4.0V
PPBUS: 12.4V
PP3V3_G3H_RTC: 3.29V
PP3V3_G3H: 3.21
VIN_RTC>VIN_RTC_UPPER_TRESHOLD
PP1V8_SLP_S2R: 1.77V
PMU_CLK32K_SOCK: Unknown
PP1V8_AWAKE: 1.77V
PP1V8_SLPS2R_PMUGPIO: 1.77V
PP1V1_SLPS2R: 1.1V
PP0V8_SLPS2R: 0.79V
PP0V82_SLPDDR: 0.79V
PP3V3_AWAKE: 3.24V
PPVDDCPUSRAM_AWAKE: 3.16
PP0V9_SLPDDR: 0.88V
P1V1_SLPDDR_SOCFET_EN 1.78 (A BIT HIGH)
PP1V1_SLPDDR: 1.08V
H9M_24MHZ_CLK: UNKNOWN
PP1V2_AWAKE: 1.19V
PPVDDCPU_AWAKE: 0.75V
PMU_SYS_ALIVE: 1.75V
PMU_ACTIVE_READY: 1.77v
PMU_COLD_RESET_L: 1.76V
H9M LOAD SECURE ROM, SMC BATTERY TRAP
PMU_PVDDMAIN_EN 0V
P3V3MAIN_PGOOD 0V
PP3V3_G3H_RTC: 2.97V
PMU_CLK32K_PCH: UNKNOWN
PCH_RTC_RESET_L: 2.97V
P5VG3S_EN: 0V
PP5V_G3S: 0v
P3V3G3S_EN: 0V
PP3V3_G3S: 0V
PP1V8_G3S: 0.31V
P5VG3S_PGOOD: 0V
PMU_CLK32K_WLANBT: UNKNOWN
I am unsure of the cause of the missing voltages after the final segment. What lines can I check to see if there are missing requirements for the U7800 to spit out some of the missing enable signals and voltages? Any tips would be appreciated. Even though I found no corrosion where the U7800 chip is I still tried reflowing it with no luck.
I am having the issue of no 20V on the USB C port. USB-C Stays at 5V permanently. Current draw is 130mA. If I connect and disconnect in a certain way I can sometimes obtain a 300mA draw.
This laptop came in for water damage and although there was some corrosion it was not very bad. The board was ultrasonic cleaned but is not powering on. Laptop was having 20V prior to cleaning but there was no signs of charge or power with 0 or near 0A draw. Now there is only 5V 130mA draw.
Most of the corrosion found was around U8510 where it was cleaned and nothing too detrimental was found. This IC seems in charge of turning on the display panel and should not have much to do with our USB C issue. The worst of the corrosion was here and the biggest victim was a large capacitor where one end was completely eaten away. All traces and BGA balls look fine after cleaning and component replacements. This circuit is found next to LCD display connector though this connector itself does not show corrosion.
Some corrosion was found around one CD3127 chip but was fairly light and was easily cleaned. Chip was re-flowed with no luck.
A bit more corrosion was found on the bottom side of the board where U7800 is located. This corrosion was also light and the capacitors affected were only lightly corroded and could be re-tinned. No shorts found among these capacitors.
There was a bit more corrosion around U6903 which seems in charge of producing PP3V3_G3H RTC which was cleaned up and is working fine. Corrosion here was also fairly light.
Among the anomalies found are:
A bit of heat coming from the T2 chip while the USB C charger is plugged in and drawing 130mA. Same goes for when I can get the machine to draw 300 by quickly disconnecting and re-connecting the USB C ports. Behavior is the same on both ports. Heat on T2 is fairly light, warm at best.
The 5V LDO on U7650 was not functioning and was at complete zero though no short was detected. This chip produces PP5V_G3S and PP3V3_G3H. Out of the two PP5V_G3S is missing. PP3V3_G3H is present. Upon replacement of this chip 5V LDO partially returned at 2.75V. A second chip was installed and LDO still stays at 2.75V. No obvious short can be found on line. The filter capacitor immediately at the output of this LDO line was replaced with no luck. This does not seem to be connected to anything.
Enable signal for PP5V_G3S is missing.
LDO voltages at CD3217 chips are present and there are no obvious shorts around these two chips.
Using the power sequencing graph attached below the following voltage measurements were observed. Measurement list is up until the segment where I found issues.
VALID EXTERNAL POWER SOURCE, BATTERY OR CHARGER >4.0V
PPBUS: 12.4V
PP3V3_G3H_RTC: 3.29V
PP3V3_G3H: 3.21
VIN_RTC>VIN_RTC_UPPER_TRESHOLD
PP1V8_SLP_S2R: 1.77V
PMU_CLK32K_SOCK: Unknown
PP1V8_AWAKE: 1.77V
PP1V8_SLPS2R_PMUGPIO: 1.77V
PP1V1_SLPS2R: 1.1V
PP0V8_SLPS2R: 0.79V
PP0V82_SLPDDR: 0.79V
PP3V3_AWAKE: 3.24V
PPVDDCPUSRAM_AWAKE: 3.16
PP0V9_SLPDDR: 0.88V
P1V1_SLPDDR_SOCFET_EN 1.78 (A BIT HIGH)
PP1V1_SLPDDR: 1.08V
H9M_24MHZ_CLK: UNKNOWN
PP1V2_AWAKE: 1.19V
PPVDDCPU_AWAKE: 0.75V
PMU_SYS_ALIVE: 1.75V
PMU_ACTIVE_READY: 1.77v
PMU_COLD_RESET_L: 1.76V
H9M LOAD SECURE ROM, SMC BATTERY TRAP
PMU_PVDDMAIN_EN 0V
P3V3MAIN_PGOOD 0V
PP3V3_G3H_RTC: 2.97V
PMU_CLK32K_PCH: UNKNOWN
PCH_RTC_RESET_L: 2.97V
P5VG3S_EN: 0V
PP5V_G3S: 0v
P3V3G3S_EN: 0V
PP3V3_G3S: 0V
PP1V8_G3S: 0.31V
P5VG3S_PGOOD: 0V
PMU_CLK32K_WLANBT: UNKNOWN
I am unsure of the cause of the missing voltages after the final segment. What lines can I check to see if there are missing requirements for the U7800 to spit out some of the missing enable signals and voltages? Any tips would be appreciated. Even though I found no corrosion where the U7800 chip is I still tried reflowing it with no luck.
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