Repair of alien p18e laptop without charging

Repair of alien p18e laptop without charging

Machine model: Alien p18e

Board No.: la-9931p

Fault phenomenon: unable to charge, discharge normal

Maintenance process: after dismantling the machine for inspection, it was found that the problem was not simple. When the customer sold it to me, he said it had not been repaired, but the battery was broken. As a result,Current protection isolation had been dried and rotten.

Maintenance of alien p18e notebook without charging Figure 1

Since the charger can be turned on, it shows that Current protection isolation should not be a problem. Master Lu suggested that the remaining time for charging was too long, so he thought whether the charging current detection fault was right or not. When the charging chip pin was detected, it was found that VCC was abnormal.

Maintenance of alien p18e laptop without charging Figure 2

On the two resistors connected with the current detection resistor, one measured 20V and the other only 1V. After disconnecting the power supply, it was found that the CSSP pin was very low to the ground diode value.

Maintenance of alien p18e notebook without charging Figure 3

After disconnecting the resistance and Capacitor connected to the charging chip, the resistance Capacitor measured separately is normal. Since CSSP is through the hole from this place, it is supposed that Short circuit in the half layer may be broken. Therefore, the original resistance pin is disconnected and welding Jump wire is renewed.

Maintenance of alien p18e notebook without charging Figure 4

After Jump wire, CSSP and CSSP VCC returned to normal. After the battery was connected and the original adapter was inserted, the charging Inductor waveform was measured.

Maintenance of alien p18e notebook without charging Figure 5

So the machine was installed and entered into the system. The charging was normal. At this point, the maintenance was finished.

Maintenance of alien p18e notebook without charging Figure 6