HP 6710b - Battery light is flashing orange

Hello,

I'm seeking your advice because I have a battery issue.
I just bought a HP Compaq 6710b laptop that seems to have been sitting in a closet for a long time.

At first, when the laptop was plugged in, the battery icon indicated "charging" but didn't change (e.g., 82% continuously), and even on discharge, 1 hour after unplugging, it was still 82%. I let the battery drain completely, then replugged it and did a full charge; the value indicated on the battery icon rises properly to 100%.

Now, the charging and discharging seem correct (about 2 hours of charging for 3 hours of actual autonomy), the battery light is solid orange during charging and when it nears 100%, the light turns solid green. But when the laptop is off and unplugged, the battery light blinks orange; when I press the ON button of the laptop, nothing happens, but as soon as I plug in the power supply, the laptop turns on without pressing the ON button. Sometimes the battery is recognized, other times not, and by disconnecting/reconnecting the battery, the laptop recognizes it again.

I saw in other posts that this might be due to prolonged inactivity and to solve it, you need to remove (with the laptop off) the battery and the power supply for a while, turn on the laptop without the battery, turn off the laptop, put the battery back in, and start the laptop. This doesn't work for me.

Is there any specific manipulation I should do?

Thank you in advance.

Edit: Oh yes, and I also get this message when I unplug the power supply:
"The hardware can be safely removed: Broadcom NetLink Gigabit Ethernet device"
And when I plug or unplug the power cable, the laptop makes the same sound as when you plug and unplug a USB stick.

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