3.3.1 20 repair instances for HP laptop battery failures
1. HP DV7t laptop cannot charge:
Failure symptom:
  DV7 laptop cannot charge, it always stays around 10%, and when connect external power supply, the fan rotates very quickly, and when I stop mouse on the power icon, it shows the battery cannot charge…
Solution:
  This failure symptom obviously belongs to the description in 10 flow chart; make sure of the repair path according to the repair method, finding that it accords with the sequence: Start->A-1->B-1->B-3->B-4; however, there’s no special function to charge battery in HP laptop’s CMOS setup, and by general method, first turn off the laptop, pull out external power, and then uninstall battery; after that, press the power button of the laptop for 15 to 20 seconds above, and at last, reconnect battery and power supply, after that, everything become normal again, if it still fails, then suggest trying several times.
Prompt: you could update BIOS software to optimize CMOS setup, and many times the problem that laptop could not charge could be solved by this way; however, you’d better to follow the principle that first easy and then complex. First use “General method”, this is a very important step to simplify repair process, remember: before pressing power button, make sure to cut off all power, including battery and power adapter.

2. HP nx8220 laptop could not charge:
Failure symptom:
Battery cannot charge, and the charging state shows 0. Test the battery on