Lenovo G50-70 - Not powering on

[GroundChuck]

Recently acquired this laptop, it did not come with charger so I ordered one. Laptop powered on but it would not charge the battery, continuous blinking charging LED. Laptop would work great as long as it was plugged in. 3 days later it no longer powers on, or responds in any way even if charger is plugged in.

Ordered 2nd new charger\battery, neither seem to help. Device still unresponsive.

Board: ACLU1/ACLU2 UMA NM-A272 Rev1.0
Multi-meter: Extech EX350

I have little skill with the hardware side of troubleshooting or use of a multi-meter but am eager to learn. After seeing 30 other post around the web for similar issues on this laptop, I have disassembled and gathered the following measurements.

PQ301
1-20v
2-20v
3-20v
4-5v
5-20v
6-20v
7-20v
8-20v

PQ302
1-20v
2-20v
3-20v
4-5v
5-20v
6-20v
7-20v
8-20v

PQ303
1-20v
2-20v
3-20v
4-20v
5-1.9v
6-1.9v
7-1.9v
8-1.9v

PF101
20v

JDCIN1
1-20v
2-20v
3-0
4-0
5-0

Thank you for any feedback or advice.

[Techtiger]

Re: Lenovo G50-70 - Not powering on

in page 53 of Schematic you have the PU301 IC test the voltage of pin 1 2 5 6 7 8 9 16 20 , is the voltag on Pl302 with battery ? test the power button J5/J6 page 45 for 3.3V & test the Voltage of PJ303 PJ306 page 54

[GroundChuck]

Re: Lenovo G50-70 - Not powering on

Well, I was testing the initial request of PL302 & PU301, and I must have done something wrong. Because my initial voltages for PQ301/302/303 are now all significantly different.

PL302 - shows 1.9v

PU301
1-19
2-19
5-0.01
6-2.5
7-0
8-0
9-0
16-5.9
20-19

Will repost the new results for PQ301/302/303 and then the J6/J6 data

[GroundChuck]

Re: Lenovo G50-70 - Not powering on

New measurements. Is that normal for them to change so much, or did I ruin something?

PQ301
1-19.6v
2-19.6v
3-19.6v
4-19.6v
5-20.1v
6-20.1v
7-20.1v
8-20.1v

PQ302
1-19.6v
2-19.6v
3-19.6v
4-19.6v
5-0.04v
6-0.04v
7-0.04v
8-0.04v

PQ303
1-0.04v
2-0.04v
3-0.04v
4-3.5v
5-0
6-0
7-0
8-0

PF101
20v both sides

JDCIN1
1-20
2-20
3-0
4-0
5-0

PL302
0v

PU301
1-0.04v
2-0.04v
5-0v
6-2.6v
7-0v
8-0v
9-0v
16-0v
20-19v


Still working on the J5/J6 and PJ303\PJ306

[GroundChuck]

Re: Lenovo G50-70 - Not powering on

PJ303
PJ306

Both are showing 0v


Having some difficulty determining where J5/J6 is on the board, but I'll reply once I figure it out.

[GroundChuck]

Re: Lenovo G50-70 - Not powering on

Finally found J5/J6 and both were 0v when plugged into charger.

On battery
PL302 is 14.8v
J6-2.9v
J5-2.9v

[mcplslg123]

Re: Lenovo G50-70 - Not powering on

post#4 measurements are wrong.PQ302 should have +19v on pin 5-8. You have 0v there indicating a B+ short. Pin4 gate should be lower then 19V as its a P channel mosfet-say approx 6V. I'll recommend to change the charger IC first and see if you get back correct voltage on PQ301/302. Unless and otherwise, this defect is rectified, no pint probing further.

[Techtiger]

Re: Lenovo G50-70 - Not powering on

Well, I was testing the initial request of PL302 & PU301, and I must have done something wrong. Because my initial voltages for PQ301/302/303 are now all significantly different.

PL302 - shows 1.9v

PU301
1-19
2-19
5-0.01
6-2.5
7-0
8-0
9-0
16-5.9
20-19

Will repost the new results for PQ301/302/303 and then the J6/J6 data

According to the new measurements BQ24737 voltage on pin 7 8 9 missing was this measurments done without Battery ?
Pin 7 IOUT EC will get informed total amount of overcurrent through the SMB
(CK & DA) pin 8 & 9 all this supply’s are missing due to a Short or leaking SMD
Find out PQ998A Voltage on pin 5 ? Voltage on PR326 both side ? this circuit is very important for Voltage Divider PACIN . Find out PR309 Voltage on Both side ?

New measurements. Is that normal for them to change so much, or did I ruin something?

PQ301
1-19.6v
2-19.6v
3-19.6v
4-19.6v
5-20.1v
6-20.1v
7-20.1v
8-20.1v

PQ302
1-19.6v
2-19.6v
3-19.6v
4-19.6v
5-0.04v
6-0.04v
7-0.04v
8-0.04v

PQ303
1-0.04v
2-0.04v
3-0.04v
4-3.5v
5-0
6-0
7-0
8-0

PF101
20v both sides

JDCIN1
1-20
2-20
3-0
4-0
5-0

PL302
0v

PU301
1-0.04v
2-0.04v
5-0v
6-2.6v
7-0v
8-0v
9-0v
16-0v
20-19v


Still working on the J5/J6 and PJ303\PJ306

As msplslg123 have mention the supply on PQ301 pin 4 is too high to conduct the RB Fet it should be around 6V test PQ302 PQ303 for any short Gate Drain Source, What is the Voltage on PR304 both side without Battery

[sourcebf]

Re: Lenovo G50-70 - Not powering on

hi,
I have the same probleme and I find PQ301 pin4 (gate) shorted with pin 1 2 3
change it and the job is done

thanks for the post