#1 Lenovo Thinkpad E590 - Does not turn on or charge battery
da MendUsThis • 16 febbraio 2026, 15:11
Hello,
Board markings are FE490/FE590/FE480 NM-B911 Rev 2.0.
This laptop had a burnt USB controller chip (U4201 - Realtek RTS5455). I have replaced this along with the USB C port. The USB controller chip has been programmed to suit this board by the seller.
Plugged in to the charger via a USB meter, I only have 5V at the USB port and 0A.
Have checked transistors Q4202 and Q4203 and get the following results.
Q4202 (N channel) - Red probe on Source, Black on Drain = 0.55V. probes reversed = 2.59V.
Q4203 (P channel) - Red probe on Source, Black on Drain = Overload, probes reversed = 0.41V.
Do the readings on Q4202 look OK? I was expecting to see Overload between Drain and Source, not 2.59V. I'm testing in circuit, so this may be affecting the readings.
Board markings are FE490/FE590/FE480 NM-B911 Rev 2.0.
This laptop had a burnt USB controller chip (U4201 - Realtek RTS5455). I have replaced this along with the USB C port. The USB controller chip has been programmed to suit this board by the seller.
Plugged in to the charger via a USB meter, I only have 5V at the USB port and 0A.
Have checked transistors Q4202 and Q4203 and get the following results.
Q4202 (N channel) - Red probe on Source, Black on Drain = 0.55V. probes reversed = 2.59V.
Q4203 (P channel) - Red probe on Source, Black on Drain = Overload, probes reversed = 0.41V.
Do the readings on Q4202 look OK? I was expecting to see Overload between Drain and Source, not 2.59V. I'm testing in circuit, so this may be affecting the readings.
