Lenovo legion 7 16achg6 - no power

[tommy97]

Hi,

i've got problem with Lenovo legion 7 16achg6 - no power, laptop on lab PSU does not draw any power/does not power on. While on original charger, laptop does show battery charge(orange led). After power button, top LED's are lighting up - CPU/GPU cold, only heat comes from battery mosfets (up to 45degree, which seems normal on this laptop). Checked First mosfets - correct reading Source and drain 20V - Gate 26.3V. Battery 15.4V, Bios 1.8V, Power button 3.3v. Checked on different BIOS - no change.

Board model: NM-D563 Rev 2.0 (AMD Ryzen 7)

[DeXXter]

Did u check if the oscillators around the cpu are working correctly? Those amd legion tend to fail there.

[mcplslg123]

To power a gaming laptop from dc supply you need special add on toolsas they consume a lot more power.

Always do the basic checks first.
01.Resistance to GND on all coils.
02.Voltage on all coils after pressing power BTN
03.Resistance to GND on dc-dc converts on switched rail side(commonly called VS )
04.If you have short on 1.8V VS side,then immediately discard the repair as amd cpu is bad.