GJ5CNXX is not turned on (s3 signal cannot be generated when the bridge is broken)

GJ5CNXX is not turned on (s3 signal cannot be generated when the bridge is broken).

[Fault model] GJ5CNXX

[Fault phenomenon] No boot.

[Maintenance process] I received a machine sent for repair by my peers, model GJ5CNXX, and the fault showed that it did not start.

alt Figure 1

This is a single motherboard sent for repair by peers, and the shell and accessories are not sent. The current on the single board can reach more than 300 mA, and there is no CPU power supply. The timing is here in SYS_PWROK, and there is no platform reset. The CPU power supply chip is turned on and there is no power supply. This board has a timing, and the bridge uses SR40B. We slowly check according to the timing, and found that the +0.6V_DDR power supply of the memory does not come out. Check that the turn-on of this signal is PM_SLP_s3#, but this signal doesn’t come out, that is, the s3 signal doesn’t come out, and the s4 signal is 3.3v If the S3 voltage is measured at many places on the board, it’s ok to change the bridge directly.

GJ5CNXX does not boot Figure 2

GJ5CNXX does not boot Figure 3

Remove the bridge and replace it with a new one. The test current can be up to more than 1A, and the external connection can’t be displayed. Plug in the case key of the keyboard to switch, indicating that it can be started.