Lenovo IB250MH does not trigger repair

Lenovo IB250MH did not trigger, but replaced with 32.768 crystal oscillator, and the machine returned to normal.

Machine model: Lenovo IB250MH

Fault phenomenon: No response when starting up, which means no trigger

Maintenance process: after getting the machine for measurement, there is no 3 and 5V standby power supply, the input 12V of the measurement standby chip RT6576 is normal, the linear output 3V and 5V are normal, and there is no waiting for EN1 and EN2. According to the drawing, EN1 and EN2 are started by SLP SUSs #, so it is proved that the standby conditions of Nanqiao are not met.

After checking the standby conditions of Nanqiao, RCTRST and SRTCRST were normal. After checking 32.768 crystal oscillator, it was found that there was no waveform. After welding the crystal oscillator, it was found that the startup could be triggered normally, but it could not be triggered after installation. Find a 32.768 crystal oscillator from the material plate. After replacement, the waveform is normal. After repeatedly triggering the startup, it can be started normally. It is still normal after two hours of testing. So far, the maintenance is over.