Lenovo g500 issue

[asem18]

Hello everyone.
Lenovo g500 LA-9632P / i7 / intel graphic
it's turning on ,fan spinning there is backlight but no picture , nothing on external display.
i flashed bios with 3 dump...no backlight no picture...but on external display just a picture for second than nothing than picture again in repeat ( attached picture ).
the current don t decrease from 0.80 amp and when there is this picture go to 1 amp.
what to chek else please...thank you

Schematics : https://www.badcaps.net/forum/showthread.php?t=42971

[mcplslg123]

Re: Lenovo g500 issue

External picture appears and repeat the cycle means its not detecting hdd. Check uefi/legacy settings.

[asem18]

Re: Lenovo g500 issue

Thank you mcplslg for your help...i tried without HDD..

[mcplslg123]

Re: Lenovo g500 issue

Without hdd, the behaviour is normal.Check with hdd connected whether it boots up to windows screen.

[asem18]

Re: Lenovo g500 issue

THank you again for your help..i check it with HDD connected...no backlight , no picture...but there's a picture at externe display...the lenovo logo appears ,the little small circles of win turns...after 20 secondes the internal screen light and all is turn off !..

[mcplslg123]

Re: Lenovo g500 issue

THank you again for your help..i check it with HDD connected...no backlight , no picture...but there's a picture at externe display...the lenovo logo appears ,the little small circles of win turns...after 20 secondes the internal screen light and all is turn off !..

It goes to desktop screen on external with hdd connected??

[asem18]

Re: Lenovo g500 issue

i take some measurements at LVDS1
1,2 +LEDVDD = 18.34v
7 BKOFF# = 2.6 mv
21 +3VS = 3v
24 +3VS = 3v
26 +3VS_CMOS = 3v

i learned from this site that if BKOFF# is not +3v then it is EC problem !

[asem18]

Re: Lenovo g500 issue

yes it goes , but off after 2 minutes !