Lenovo IdeaPad 320 can't turn on

[cygron]

Model : Lenovo IdeaPad 320
Board id: DG424 DG524 NM-B301 Rev1.0

Laptop can't turn on. Charging is ok. Connect with battery and adapter, charging light shows and charge. Power keys have voltage. But when press power key, laptop can't swith on. Testing with DC Supply, power comsumption is first about 0.240 Amp and then stop 0.160 Amp. BIOS flashing can't fix the problem. Need help.

Voltages on all coils,
PL401 - 3.3V
PL402 - 5 V
PL302 - 0.86V
PL3401 - 0.95V
PL3301 - 0.88V
PL701 - 1.0V
PL702 - 1.79V
PL703 - 1.39V

PJ711 - 1.24V
PJ3303 - 1.79V

[mon2]

Re: Lenovo IdeaPad 320 can't turn on

Do you have schematics and boardview files you can post of this unit?

[cygron]

Re: Lenovo IdeaPad 320 can't turn on

Do you have schematics and boardview files you can post of this unit?

https://drive.google.com/file/d/1a94...Chj_Q9vWt/view

[mon2]

Re: Lenovo IdeaPad 320 can't turn on

Ok. Focus on sheet 52/58 - PU301 operation. PU301 datasheet is attached.

1) Connect adapter and battery. Post the VCC voltage on PU301_pin 28.

2) Voltage on PD302 dual diode (3 legged SOT323 package); pin 2 ?

3) Voltage on PD302 dual diode (3 legged SOT323 package); pin 3 ?

4) ACDET voltage on PU301_pin 6 ?

5) ACOK voltage on PU301_pin 5 ?

6) PL302 pin 2 voltage ? 0.86 volts ? That is not the correct value.

Power down / remove adapter & battery. Check resistance to ground on pin 2 of PL302 - reading in ohms ?

7) With adapter connected, VIN voltage value ?

8) With adapter connected, V20B+ value ?

[cygron]

Re: Lenovo IdeaPad 320 can't turn on

1) Connect adapter and battery, VCC voltage on PU301 Pin 28 - 18.6V

2) Voltage on PD302 dual diode (3 legged SOT323 package); Pin 2 - 18.9V

3) Voltage on PD302 dual diode (3 legged SOT323 package); pin 3 - 8.29V

4) ACDET voltage on PU301 Pin 6 - 2.69V

5) ACOK voltage on PU301 Pin 5 - 3.3V

6) PL302 Pin 2 voltage - 0.86 volts (Without Battery with adapter) / 7.9V (With battery and adapter)

7) With adapter connected, VIN voltage value - 20.40V

8) With adapter connected, V20B+ value - 20.20V

[toni comp]

Re: Lenovo IdeaPad 320 can't turn on

try to jumper directly on/off pin on the motherboard without installing a keyboard

[ravi_1617]

Re: Lenovo IdeaPad 320 can't turn on

Hello, please help, Same model board NM-B301 , not starting.

Only +3.3ALW present at PL401 no power at PL402 +5ALW
No power at bios any pin.
3.3 present at J5.
Same status with battery or adaptor
Thank

[mon2]

Re: Lenovo IdeaPad 320 can't turn on

hi yaar.

1) remove all power. meter in resistance mode.

2) check the resistance to ground on PL402, pin 2.

3) with power on, what is the voltage reading of +5VALW_EN ?

4) with power on, what is the voltage reading @ PJ405 ? This is the input power rail that powers the PU402 controller.

[ravi_1617]

Re: Lenovo IdeaPad 320 can't turn on

hi yaar.

1) remove all power. meter in resistance mode.

2) check the resistance to ground on PL402, pin 2.

3) with power on, what is the voltage reading of +5VALW_EN ?

4) with power on, what is the voltage reading @ PJ405 ? This is the input power rail that powers the PU402 controller.

Thanks for your reply. Sorry for late reply,

PL402 reading started 30 k ohm,hone 230.0 k ,and reverse and stopped at 74 k Ohm

At +5VALW_EN 3.3 volt showing

@ PJ405 same as pj401 19+
I have checked around PU402 are fine .
Around 10-11 m volt at pl402

Thanks

[ravi_1617]

Re: Lenovo IdeaPad 320 can't turn on

Please reply someone, Thanks

[mon2]

Re: Lenovo IdeaPad 320 can't turn on

1) Can you confirm again the voltage @ PL402, pin # 2 ? See attached.

Since the ENABLE @ pin 12 of PU402 is logic high, this buck regulator should be enabled.

If you do not see +5V on pin #2 of PL402, check that the inductor is properly soldered and that the inductor is mating to pin # 6, 19, 20 of PU402.

The measured resistance to ground on PL402 is OK and there does not appear to be a short.

Based on the above details, seems as though PU402 is defective and should be replaced. If there is any doubt of liquid damage - consider to flux and reflow PU402 as a possible fix.

2) What is the voltage on pin # 15 of PU402 ? This is a low current LDO rail and should also be @ +5v if working properly.

3) What is the voltage on pin # 9 of PU402 ? This is the power good signal that will be high once this switching regulator reaches the high enough threshold of the +5v rail. Most likely it will be a low voltage on this signal but confirm it.

4) Voltage on pin # 11 of PU402 ?

[ravi_1617]

Re: Lenovo IdeaPad 320 can't turn on

Thank ( mon2 )for your reply I will check and update.. soon