Hello. Lenovo Legion 5 15ARH05H, NM-D281 Rev: 1.0 board
Initially dead. Inspection: the board was not touched, on EC IT8227E-192 2101-CXA there is a mini-burnout.
Replaced with the same one, flashed the EC with the official firmware (had to solder to the pins), left the main firmware (Gigadevice 25LB128DSIG) original.
When connecting the charger, the device started, gave picture and works, checked all the functions - ok.
Connected the original battery. Only on the battery the device starts for a second, lights up the keyboard backlight and turns off.
When connecting the charger (with the battery connected) lights up orange charge LED, AutoStart (as it should be without an RTC battery), lights up the keyboard backlight, turns off, AutoStart again and then repeats the cycle, that is, it does not want to work with the battery. I looked to see if the charger (BQ24780S) gives a PWM signal, there are pulses on the PL101 charge coil and they disappear in time with the above cycle. I think the battery is from 2020 year and threw in a new battery - same behavior. There is an EC exchange with the battery. I checked the charging circuits - I did not find anything criminal. The input mosfets PQ101, PQ102 are ok. The charger, batfet PQ103 is ok, I changed it - same behavior. Power supply original 230 watts, tried external power supply with the corresponding 4.65 kOhm resistor from ID to ground, same behavior. Please advice
Initially dead. Inspection: the board was not touched, on EC IT8227E-192 2101-CXA there is a mini-burnout.
Replaced with the same one, flashed the EC with the official firmware (had to solder to the pins), left the main firmware (Gigadevice 25LB128DSIG) original.
When connecting the charger, the device started, gave picture and works, checked all the functions - ok.
Connected the original battery. Only on the battery the device starts for a second, lights up the keyboard backlight and turns off.
When connecting the charger (with the battery connected) lights up orange charge LED, AutoStart (as it should be without an RTC battery), lights up the keyboard backlight, turns off, AutoStart again and then repeats the cycle, that is, it does not want to work with the battery. I looked to see if the charger (BQ24780S) gives a PWM signal, there are pulses on the PL101 charge coil and they disappear in time with the above cycle. I think the battery is from 2020 year and threw in a new battery - same behavior. There is an EC exchange with the battery. I checked the charging circuits - I did not find anything criminal. The input mosfets PQ101, PQ102 are ok. The charger, batfet PQ103 is ok, I changed it - same behavior. Power supply original 230 watts, tried external power supply with the corresponding 4.65 kOhm resistor from ID to ground, same behavior. Please advice
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