LENOVO G50 -70 power on No screen

[ghost73]

Re: LENOVO G50 -70 power on No screen

3Vs appear after switshing power button ,this is your S0 satate.It supply many others IC's .
why you don't have it on pin 20/23 !!
can you take the measue of Q24 ( D/G/S) and see like Kiraro says if thers is a short on it !

In the Q24 i have .... the 17.6 v is OK ???

[lapfix]

Re: LENOVO G50 -70 power on No screen

Nice Q24 is OK ,you have 17.6v on gate because it's N-channel , the gate must be equal or higher than the voltage on Drain .
I really don't understand what you make! do you have 3V on pin 23 and no voltage on pin 20!

[ghost73]

Re: LENOVO G50 -70 power on No screen

yes .. i have 3v on pin 23 but in pin 20 no ... (now i have with the bringe)

[lapfix]

Re: LENOVO G50 -70 power on No screen

Something is wrong/not clear !
first what do you mean by : I put a ligth in screen and i see activite .!

second at jedp connecter we have :
pin 1/2 = 20v
pin 21/22 = 3.3v
pin 20 = 0v
pin 23 = 3v
can you complete the measurements for : pin 14/16 /19 /30

UE1:
Pin 81 = ENBKL
Pin 22 =PLT_RST

JDDR1 :
Pin 30 =CPU_DRAMRST

JPWRB1:
Pin4 = LID_SW

PL9=CPU_CORE

[ghost73]

Re: LENOVO G50 -70 power on No screen

Something is wrong/not clear !
first what do you mean by : I put a ligth in screen and i see activite .!

second at jedp connecter we have :
pin 1/2 = 20v
pin 21/22 = 3.3v
pin 20 = 0v
pin 23 = 3v
can you complete the measurements for : pin 14/16 /19 /30

UE1:
Pin 81 = ENBKL
Pin 22 =PLT_RST

JDDR1 :
Pin 30 =CPU_DRAMRST

JPWRB1:
Pin4 = LID_SW

PL9=CPU_CORE

I try to take a picture ...to see what i mean

pin 30 = 3.4 v
pin 14 = 0
pin 16 = 0
pin 19 = 0

[lapfix]

Re: LENOVO G50 -70 power on No screen

i m waiting for the other mesearments that i'm saking for !!

[ghost73]

Re: LENOVO G50 -70 power on No screen

UE1:
Pin 81 = ENBKL = 50Ω
Pin 22 =PLT_RST = 3.4 V

JDDR1 :
Pin 30 =CPU_DRAMRST = 0V

JPWRB1:
Pin4 = LID_SW : 6.6 V

PL9=CPU_CORE

[ghost73]

Re: LENOVO G50 -70 power on No screen

This line blink in the screen

[lapfix]

Re: LENOVO G50 -70 power on No screen

Ghost , take again the measures , in voltage please !

Pin 81 = ENBKL = 50Ω
Pin4 = LID_SW : 6.6 V..are you sure !!

DRAMRST must be 1.35v ,without it no display.

Since you are getting PLt_RSt means almost everything is ok in power sequence.

there's a a resistance and capacitor between CPU and Pin 30 (JDDR) , what's the voltage for both side of RC22, and is CC1 short to ground.

Make sure your problem NOT on LVDS cable or LED panel. Make sure you're using known good DDR3L

At last flash a known good bios ,it is very likely to solve your problem.

[ghost73]

Re: LENOVO G50 -70 power on No screen

Ghost , take again the measures , in voltage please !

Pin 81 = ENBKL = 50Ω
Pin4 = LID_SW : 6.6 V..are you sure !!

DRAMRST must be 1.35v ,without it no display.

Since you are getting PLt_RSt means almost everything is ok in power sequence.

there's a a resistance and capacitor between CPU and Pin 30 (JDDR) , what's the voltage for both side of RC22, and is CC1 short to ground.

Make sure your problem NOT on LVDS cable or LED panel. Make sure you're using known good DDR3L

At last flash a known good bios ,it is very likely to solve your problem.

Sorry
Pin 81 = ENBKL = 0V I try to test it again
I found the RC22 and i send you the measures.

i dont have programmer
I have 2 cable for LVDS ,, and two panel i am sure about this ...
The DDR3L test OK ..

[ghost73]

Re: LENOVO G50 -70 power on No screen

well
i take new measures .. In JDDR1 the number is 2-4-6
the last measures is wrong

This is correct
JDDR1 30 = 1.37 V
in the image u see the RC22 and CC1 .