lenovo nm-c171 no power

[nassih]

hi guys i have this lenovo laptop model ideapad s145 motharboard : fs44a&fs54a nm-c171 rev 1.0, power on but no fan spin no display no vcccore no voltage on bios chip also on RAM but i have:
+3VALW
+5VALW
+1.8VALW
+0.775VALW
+0.95VALW

[nassih]

Re: lenovo nm-c171 no power

schematic if needed

[JaroTech]

Re: lenovo nm-c171 no power

Follow the power sequence on page 40 to see what voltages are missing.

[mcplslg123]

Re: lenovo nm-c171 no power

I'll start with checking the requirement of Ram IC.

[nassih]

Re: lenovo nm-c171 no power

OK i Will spart checking power rails
tanks

[nassih]

Re: lenovo nm-c171 no power

hello, I noticed that laptop it works with battery not with adapter but if I connect battery and adapter it doesn't work I noticed that the outputs +3VS_SW and +5VS_SW are missing with adapter in.

[mon2]

Re: lenovo nm-c171 no power

Check the usual 2 x DCin mosfets.

As a quick test - just replace the 2nd DCin mosfet (PQ202). This is the one that often gets killed.

[nassih]

Re: lenovo nm-c171 no power

ok i will try tanks

[nassih]

Re: lenovo nm-c171 no power

hello the problem was in SUSP# line which is present on battery and not on adapter in i replaced Q6 and its working now tanks mon2,mcplslg123