Hi all
We have in a HP ProBook 445 G8 laptop with AMD Ryzen 7 CPU. When power is connected the power LED light blinks 5 times then stops. Normally HP laptops will blink this LED 10 times as it does a self test when the AC adaptor is inserted. So there must be some sort of short somewhere.
The battery doesn't charge, and is erratic on the MM voltage. Bench PSU LED pulsates when the battery is connected also. So the fault must be on the charging circuit?
I have gone around the board with a MM and cant find anything
Windows shows the battery fine, but no charging symbol.
If battery is disconnected from the motherboard the LED on the charger stays normal and the laptops powers up fine just using the HP charger.
Battery charges fine in another laptop.
So must be a charging circuit fault. Thing is I cant find a schematic of this motherboard
Motherboard is: DA0X9QMB8E0 Rev E
I`m wondering if its the BQ24800 chip? Seems to control battery charge etc:
The BQ24800 is a buck battery charge controller that performs a number of functions, including:
Battery charging and discharging
The BQ24800 can quickly transition between charging and discharging batteries to prevent adapter crashes.
Battery boost mode
When no adapter is present, the BQ24800 can support battery-only boost mode.
System power source selection
The BQ24800 uses two charge pumps to automatically select the system power source.
System power management
The BQ24800 monitors system power, battery discharge current, and adapter current. It can then throttle back CPU speed or reduce system power when needed.
Charge voltage and current regulation
The BQ24800 can regulate charge current and voltage through SMBus.
The BQ24800 can charge 1–4 series Li+ cells. It has an input voltage range of 4.5–24 V and a programmable output of 2–4 cells charge voltage and 128-mA to 8.128-A charge current.
Any ideas folks?
Many thanks
We have in a HP ProBook 445 G8 laptop with AMD Ryzen 7 CPU. When power is connected the power LED light blinks 5 times then stops. Normally HP laptops will blink this LED 10 times as it does a self test when the AC adaptor is inserted. So there must be some sort of short somewhere.
The battery doesn't charge, and is erratic on the MM voltage. Bench PSU LED pulsates when the battery is connected also. So the fault must be on the charging circuit?
I have gone around the board with a MM and cant find anything

Windows shows the battery fine, but no charging symbol.
If battery is disconnected from the motherboard the LED on the charger stays normal and the laptops powers up fine just using the HP charger.
Battery charges fine in another laptop.
So must be a charging circuit fault. Thing is I cant find a schematic of this motherboard

Motherboard is: DA0X9QMB8E0 Rev E
I`m wondering if its the BQ24800 chip? Seems to control battery charge etc:
The BQ24800 is a buck battery charge controller that performs a number of functions, including:
Battery charging and discharging
The BQ24800 can quickly transition between charging and discharging batteries to prevent adapter crashes.
Battery boost mode
When no adapter is present, the BQ24800 can support battery-only boost mode.
System power source selection
The BQ24800 uses two charge pumps to automatically select the system power source.
System power management
The BQ24800 monitors system power, battery discharge current, and adapter current. It can then throttle back CPU speed or reduce system power when needed.
Charge voltage and current regulation
The BQ24800 can regulate charge current and voltage through SMBus.
The BQ24800 can charge 1–4 series Li+ cells. It has an input voltage range of 4.5–24 V and a programmable output of 2–4 cells charge voltage and 128-mA to 8.128-A charge current.
Any ideas folks?
Many thanks
Comment