20V / 0-5mA | 820-00850 (A1989)


Staff member
Looks like board tries to start and restart because T2 detects a problem; possibly short on a secondary voltage.
All USB-C ports have the same behavior?
All 4 ports same behavior.
I noticed that PP5V_G3S isnt stable.
Note: I tried already T2 restore/review no success always ends with an error.


Staff member
If USB-C meter restarts, means no stable PPBUS_G3H; no way to complete DFU.

Check for short on all big coils; including "small" ones for SSD.
Values = diode mode
L7220 = 0.004-5
L7210 = 0.004-5
L7410 = 0.004-5
L7420 = 0.004-5
L7430 = 0.004-5
L7270 = 0.022
L8102 = 0.120
L7702 = 0.110
L8100 = 0.200
LB700 = 0.495
L7600 = 0.390
L7660 = 0.410
L7030 = 0.495
L8410 = 0.850
L3500 = 0.380

L7220, L7210, L7410, L7420, L7430 .. I assume they are low because they are on the CPU side, right?


Staff member
All values look good.

"including "small" ones for SSD"

If no short on coils, check if any pulses at least.
Also check for short/pulse at output voltages from page 78.
Sry for my late reply ....

L9080 = 0.373
L9020 = 0.333

PPBUS_G3H = 12.28V when USB-C output is 5V / 0.16A
PPBUS_G3H = 1.2V when USB-C output changes to 19.4V / 0.05A

Bad ISL?


Staff member
PPBUS_G3H drops when swithces from 5V to 20V points to problems with some secondary supply.
Is also possible that one I/V SMC sensor is triggered and SMC cycles power.
Can you turn it on in SMC bypass mode?
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