MacBook Pro A1708 Not turning on, no current draw at 20V with no shorts repair: Difference between revisions
(Created page with "{{stub}} {{Repair Guide |Device= |Affects parts= |Needs equipment= |Type= |Difficulty= }} ==Problem description== <nowiki>#</nowiki>incomplete thumb|Example image (Figure 1) -- No image yet. Help expand this page by uploading it! ==Symptoms== *Not turning on *Drawing 0A (no current) on 20V as measured by USB-C meter ==Solution== ===Diagnostic Steps=== ==== Check for low resistance to ground on SMBUS_SMC_5_G3H_SDA or SMBUS_SMC_5_G3H_SCL =...") |
(No difference)
|
Revision as of 09:08, 27 October 2023
This article is a stub. You can help Repair Wiki grow by expanding it
MacBook Pro A1708 Not turning on, no current draw at 20V with no shorts repair | |
---|---|
Device | |
Affects part(s) | |
Needs equipment | |
Difficulty | |
Type |
Problem description
#incomplete
Symptoms
- Not turning on
- Drawing 0A (no current) on 20V as measured by USB-C meter
Solution
Diagnostic Steps
Check for low resistance to ground on SMBUS_SMC_5_G3H_SDA or SMBUS_SMC_5_G3H_SCL
On older MacBooks, this would result in no battery recognition and a lower voltage on PPBUS_G3H—on USB-C models, it actually results in the machine not turning on at all. Can be caused by a tiny speck of conductive material in the battery connector.
Check for 0.4 V in diode mode on SMBUS_SMC_5_G3H_SDA and SMBUS_SMC_5_G3H_SCL (red probe on GND)
if it's higher the I2C signals will look funny, not going just between 0 and 3.3 V. Check D6950—it can be blown when the SMC goes.
Check voltage on PPBUS_G3H
If you have no or low voltage on this rail, check the repair steps below.
Repair Steps
low resistance to ground on SMBUS_SMC_5_G3H_SDA or SMBUS_SMC_5_G3H_SCL
Clean the conductive material, Video
0.4 V in diode mode on SMBUS_SMC_5_G3H_SDA and SMBUS_SMC_5_G3H_SCL (red probe on GND)
#incomplete
Low or no voltage on PPBUS_G3H
It could be bad/dead ISL9239. Also check for ≈2.4 Ω on the two ISL9239 current-sensing circuits. If any of the 1 Ω or current-sensing resistors are blown, replace them first, or you will re-kill any new ISL9239 you try!