Lenovo 320 -15AST not power on !

[lapfix]

Hello folks
Lenovo 320 -15AST
Motherboard = NM-B321
AMD with DDR 4

Lenovo no backlight,no picture Fan not turning on even the CPU get hot after a moment , not display at extern too.

PSU =0.300 amp .
PL601/602 = 3/5 valaw ok
Pl 2201 = +APU_CORE_NB = 0.897 v
Pl 2202 = +APU_CORE = 0.897 v
Bios Pin 8 = 1.8 V
5/3 VS ok / 1.8VS ok / 0.95VS ok / 0.6 VS ok /

PLT_RST = UL1 =Pin 19= 3.4v

UE =
pin 34 = EC_APU_ALWEN = 3.4V .

Ram = +1.2V ok / +VDDSPD = 3.4V ok / +2.5V OK

Flashed bios from web site /other site same issue , changing Screen same thing

U7 = +3VS ok but no PCH_ENVDD.

So , what i miss to check else !!

Thank you

[Techtiger]

Re: Lenovo 320 -15AST not power on !

QC9 is not in the MB ? what is the Resistance to GND PCH_ENVDD ? R35 100k is good ? as for the power sequence KBRST# should get reset last !

[lapfix]

Re: Lenovo 320 -15AST not power on !

Thank you Tech .
Yes QC9 didn't exist.

U7 Resistance to GND =
Pin 4 = PCH_ENVDD = 69.1Kohm.
R35 = 67.8 Kohm.

KBRST# when charger connected = 0v...press power = 3.4v

[Techtiger]

Re: Lenovo 320 -15AST not power on !

find out for VGA_PWRGD line is ok or not

[lapfix]

Re: Lenovo 320 -15AST not power on !

No components to test , most of themps are with @ = don't exsist .
Une merde ..
i find the place of DV3 - don't exist - and try to take measurements (voltage and resistance) at his pad.

Voltage / diode mode see the pictures

[lapfix]

Re: Lenovo 320 -15AST not power on !

Update
UE1 =
pin 34 = EC_APU_ALWEN = 3.4V
pin 106 = EC_GFX_PWRGD = 3.1v than decrease ....i add R 10kohm = 3.4v
pin 97 = EC_VR_ON = 3.4v
pin 99 = EC_SYS_PWRGD = 3.4v
pin 109 = LID_SW# = 3.4v
pin 108 = ACIN# = 3V
pin 78 = VR_APU_PWRGD = 3.4V
pin 99 = EC_SYS_PWRGD = 3.4v
Pin 19 = PLT_RST = 3.4v

[Techtiger]

Re: Lenovo 320 -15AST not power on !

if you can test voltage or from oscilloscope
LPC_FRAME#
LPC_AD3
LPC_AD2
LPC_AD1
LPC_AD0
CLK_PCI_EC

[lapfix]

Re: Lenovo 320 -15AST not power on !

sorry i don't have oscilloscope

LPC_FRAME# = 3.4v
LPC_AD3 = 3.3v
LPC_AD2 = 3.3v
LPC_AD1 = 3.3v
LPC_AD0 3.3v
CLK_PCI_EC = 1.7v