Lenovo T14 gen 2 NM-D352

[dancu.alexandru@gmail.com]

Hello,

i have a weird problem with a lenovo T14 that only randomly powers on. All the voltages are present, nothing seems to be shorted, battery charges.

When i press the power button it tries to boot for about 2 seconds thant the usb meter restarts an current draw remains at about 50 mAh. somethimes it boots to windows but very rare.

After the usb meter restarts the power button blinks 3 times.

Could someone please help with any suggestion, what to check.

Thank you

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance to ground on each and very inductor on the board. Each inductor is linked to a local power supply. Hunting for a lower than normal resistance which denotes there is a shorted part on that power rail and causing an excessive current draw to be measured.

[dancu.alexandru@gmail.com]

These are the mesurements:

PL0701 OL
PL1101 77,8
PL0901 19,7
PL0902 19,7
PL1001 19,7
PL0401 OL
PL0201 OL
PL0202 OL
PL0601 59,8 - NO RAM, 21,8 - WITH RAM
PL0301 OL
PL0501 OL

[questore]

Hello,

i have a weird problem with a lenovo T14 that only randomly powers on. All the voltages are present, nothing seems to be shorted, battery charges.

When i press the power button it tries to boot for about 2 seconds thant the usb meter restarts an current draw remains at about 50 mAh. somethimes it boots to windows but very rare.

After the usb meter restarts the power button blinks 3 times.

Could someone please help with any suggestion, what to check.

Thank you

1. Does this mean 1 orange 3 white led code?

[dancu.alexandru@gmail.com]

1. Does this mean 1 orange 3 white led code?

only 3 white and orange at the charging port

[questore]

only 3 white and orange at the charging port

Try Reprogramming BIOS.
Most time i have encountered 3 white led Error it was a faulty BIOS (sometimes even faulty BIOS IC) or faulty EC firmware

[dancu.alexandru@gmail.com]

Try Reprogramming BIOS.
Most time i have encountered 3 white led Error it was a faulty BIOS (sometimes even faulty BIOS IC) or faulty EC firmware

i did reprogramed bouth bios chips but no change.

the weird thing is, if i let the usb cable connected, after aprox 5 minutes it starts. if i let it sit without power connected it dosn`t start. if it starts and i turn it off it doesn`t start anymore, only if i let it sit for another 5 min connected to usb charger

[questore]

i did reprogramed bouth bios chips but no change.

the weird thing is, if i let the usb cable connected, after aprox 5 minutes it starts. if i let it sit without power connected it dosn`t start. if it starts and i turn it off it doesn`t start anymore, only if i let it sit for another 5 min connected to usb charger

Sound like your usb-c PD controller is acting wierd.
Try measuring the voltages on the input mosfets gate and drain when the USB meter shows restarting.
Is your battery really charging or just the led indicator is lighting up?