Charging - Ericsson GF 768 Troubleshooting Manual

Troubleshooting guide

4. Charging.

4.1 Type of charging fault.
Make a visual check of the battery and system connector. Replace if needed. Insert a fully charged battery and
start the phone.
• If it doesn't start, go to chapter 6.
• If the phone starts and shows that it's charging immediately, go to 4.2.
• If the phone doesn't show that it is charging immediately, turn it off and insert a charger into the system con-
nector.
• If the phone starts, indicates that it is charging and lights the red top indicator then there's probably nothing
wrong with the phone. To verify this, test the phone as described in 4.1.1.
• If the phone starts, indicates that it is charging but doesn't light the red top indicator, go to chapter 5.
• If it doesn't start, go to 4.3.
• If it starts but doesn't charge although it indicates that it does, go to 4.4.
4.1.1 Verifying the charging function.
Connect an ordinary battery to the phone. The voltage of the battery must be so high that you can start the phone
with it. Otherwise the charging doesn't start immediately.
Cut the cable from a charger and make a charging test cable.
Connect the charging test cable to a power supply that shows the current consumption. Make sure that the DCIO
pin is connected to the positive outlet of the power supply. As an alternative you can connect an ordinary battery
charger in serial with an ampere meter.
Set the power supply at 7.6V and a current limit of 700mA.
Connect the charging test cable to the system connector of the phone and check the current consumption.
• There's nothing wrong with the charging function if the phone starts, indicates in the display that it's charging
and switches between 700mA (500-800mA depending on charger model if using the alternative solution) and
~5mA with a few seconds interval.
Every time you repair a charging fault you have to verify the charging function as described above.
4.2 Indicates charging without charger inserted.
Open the phone and check for water damage. Both sides of the circuit board are shown in fig. 4.1.
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