Charging Fault - Ericsson T18s Trouble-Shooting Instruction

6 Charging fault

6.1 Type of charging fault.
Perform a visual check of the battery connector and the system connector. Replace
if necessary. Start the phone using the On/Off-key and a fully charged battery.
• If it doesn´t start at all, proceed to chapter 3, "Doesn´t start"-fault
• If the phone starts and shows charging at once, proceed to section 6.2.
• If the phone doesn´t show charging, turn it off and connect a battery charger to
6.1.1 Verification of the charging function.
Cut a cable from a battery charger to make a charging test cable.
Connect the charging test cable to a power supply that shows the current consump-
tion. Make sure the positive side from the power supply connects to DCIO (the
lonely pin on the system connector, pin 12).
Set the power supply to 7.6V and the current limit to 700 mA.
Another method is to use a regular battery charger with an ammeter connected in
series.
Connect the charging test cable to the system connector of the phone and check the
current consumption. It should be approximately 20 mA when the battery isn´t con-
nected (Notice! This is only accurate on T18, not on older types of phones). Then
the "Trickle Charge" function in N450 (class C) is active, i.e. the charging that is
made on a completely empty battery until the voltage of the battery is high enough
(>4,4 V) to start the rapid charging .
Attach a normal battery (not a so-called dummy battery) to the phone. The voltage
of the battery should be high enough to start the phone, otherwise the verification
will take too much time.
the system connector.
* If it starts, shows charging and the red top indicator flashes, the phone is
okay.
* If it doesn´t start, proceed to section 6.3.
* If it starts, but doesn´t show charging, proceed to section 6.4.
* If the phone starts and shows charging but the top indicator doesn´t flash,
proceed to the chapter 9; "Illumination, buzzer and vibrator"-faults.
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T18s, T18sc Standard Electrical Repairs
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