Yoga 7-15ITL5 Laptop (ideapad)

[jimmy2022]

Hello.
I posted in the wrong place. i think this is the right place.

Yoga 7-15ITL5 Laptop (ideapad)
gyg51 rev 1.0

https://pcsupport.lenovo.com/gb/en/p...ds/driver-list


the mosfet in the picture is reaching temperatures near 70 c.
is it possible that the battery is drawing too much current ?
the laptop is powering up and charging.

[jimmy2022]

I wanted to clarify that
The mosfet reaches near 70 c when charging, is this nornal?

[mon2]

What are the temps of the other mosfets driven by this charger IC. The temp is high.

[jimmy2022]

as you can see when the laptop is charging the temp is below 60 c. when the laptop powers up, after a few min the mosfit aswell as the bq chip increase in temp. none of the other mosfets seem to be reaching similar temps as what can be seen in the pictures. pq301 temp after pwr on = 70 c. i am wondering whether the battery is knackered ?

[mon2]

Remove all power & no battery. Meter in resistance mode.

Check the resistance of the PQ301 mosfet:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post each measurement. Checking if this mosfet is leaking. If your meter is a manual select type, use a higher measurement scale if the display shows 'OL' for overlimit.

[jimmy2022]

Hello mate

meter set to 20k, the readings are as follows:

s - d = 18.88 k

s - g = 0

g - d = 18.88 k

[mon2]

Can you link the schematic and/or post it inside the schematic forum for reference?

Each is a low measurement for a good mosfet. Suggest to flux and remove it off the board. If available, replace this mosfet. Many different mosfets can be used to replace this one.

Would you have access to donor boards? The mosfet must be a N-channel; same physical size of 3x3; 30V rated (common type); as high current support as available for your budget. TI has some great ones with high current ratings.

AONR36368 Alpha & Omega Semiconductor Inc. | Discrete Semiconductor Products | DigiKey

[jimmy2022]

Schematic
https://www.badcaps.net/forum/troubl...-schematic-boa

i did change it with a spare 32314 because pq301 gave up all of a sudden. Same problem. Temp high.

gate voltage is 22 v.
is it possible that the bq chip is receiving a wrong signal?

[mon2]

This is a N-channel mosfet so the GATE voltage should be higher than the voltage being passed through the source & drain pins to enable.

GATE voltage = adapter voltage + REGN voltage = ~19v + ~6 volts = ~25 volts to enable the N-channel mosfet.

Remove all power. Measure the resistance to ground on the source pins (1-2-3) of PQ301.

Was PU301 ever replaced or reworked? Confirm that there is no short between pins 29 & 31 of the charger IC.

One pin controls the high side mosfet; the other controls the low side mosfet.

Confirm the resistance across the low side mosfet like before but for PQ302.

[jimmy2022]

my uncle shop has closed so i'll have to check this tomorrow morning. i forgot to say yesterday that the gate for TBTB_GATE_VBUS was 27 volts. is this normal? to my knowledge pu301 was not reworked/replaced.

[mon2]

The voltage seems a bit high.

Are you using the official power adapter for this logic board?

Share the voltage to ground of the charger IC:

REGN ; should be ~6 volts
pin 1 = CHARGER_VBUS

[jimmy2022]

Regn = 6v
same official pwr adapter from lenovo
v to ground = 0.00
pq301 gate now reads = 10 .5 (no bat connected)

meter set to 20k . Black line to 123 for pq301 gives reading 18.6k. Reversed = no reading.


Pq302
>source (1-2-3) & drain (5-6-7-8)

18.3 k meter set to 20k

>source (1-2-3) & gate (4)

123= ground
it reads 7.3 k



>gate (4) & drain (5-6-7-8)

7.2 k


for gates of these two mosfets, no shorts.

[mon2]

Double check the voltage to ground of pin #1 on the charger IC. It cannot be 0 volts if you have a voltage on REGN.

[jimmy2022]

19.94 v