gjgjh

Here's a solution that may help fix and repair Nokia N78 keypad failure or malfunction . If you already tried to replace the keypad flex cable but the problem still exists, this solution below will show you the keypad filter IC that is being connected to eah particular keys within the keypad matrix. N78 Keypad Filter IC connection tracks You may trace each particular line paths for deep keypad repair troubleshooting.

This repair solution below may possibly help fix and repair a damaged Nokia N78 displays like white screen, blues screen, garbled, blank or black screen and some related display problems and failure. N78 Display problem solution N78 Display IC jumper ways solution Repair Hints: There are two Display filtering chips used in the circuit, if already tried and replaced those both filter IC you may then also rework or replace the Display IC marked with number 3.

This solution show the two filter coils and ESD filters that needs to be check or by then replace if there is no audio sounds can be heard over the earpiece speaker On Nokia N78. Ensure that the speaker is working fine before trying to check and replace those components showed on the solution picture. Nokia N78 Earpiece Speaker Problem Solution ( No audio sounds repair) Those components are composed of a chip filter coils and an ESD filter that looks like a resistor and mounted on the top left side of the PCB board.

Here's the solution that may possibly help fix and repair a microphone failure on Nokia N78 cell phone handset. In Nokia N78 the microphone line track is connected over the keypad flex cable wire connection. If something went wrong and the microphone failed to have an audio signal output during transmission , The problem may possibly lies on a faulty mouthpiece microphone, a damaged flex cable and a faulty microphone signal line paths. This solution below shows the microphones line tracks that needs to be trace after ensuring that the microphone is okay and the flex cable is also okay. Nokia n78 microphone failure solution The microphone's positive terminal line tracks is connected on pin 22 of the keypad pin connector, while the negative terminal is on the PCB grounds. There is also a bypass capacitor connected to it, if the capacitor is oxidated or shorted due to a wet damaged this also result to microphone failure problem.

Here's a complete line tracks of Nokia N78 charging circuit that may help fix and repair Not charging issues such as Charger No Response and Fake Charging. The solution below shows the corresponding components that needs for check up and replacement if found damaged. Nokia N78 Charger No response solution When a charger is being plug-in but there is no indication shows on the LCD screen Display. The problem may lies on an open chip fuse or a shorted diode. see picture above.. But ensure first that the charging pin connector is perfectly clean and not damaged before trying to check or replace the above showed mounted components. IF the chip fuse, filter coils, chip diodes and capacitors is okay the problem may possibly lies on the Charging IC (BETTY IC). Try to reflow/rehea and rework before replacing it. A faulty Charging IC may also result to a fake charging, it means that it  shows a charging indication on the LCD screen display but the battery does not charge up at all.

Here's the solution that may possible fix and repair Nokia N78 Charger not supported problem. This is caused by a damaged battery temperature resistor (BTEMP). This resistor has a value of 47K, by replacing it might help fix the problem. Nokia N78 Charger Not supported solution N78 BTEMP Resistor location

Here's a solution for nokia N78 ringer and hands free speaker not working or no sounds can be heard on it. This solution shows the left and right speaker circuit components connections. Nokia N78 Ringer and Hands Free speaker No audio sounds solution There is an audio amplifier IC that drives and boosts the audio signals before it goes trough to the left and right speakers. The audio data  signal is filtered by filter coils and an input capacitors. Repair hints: 1. Check and ensure that the speaker is working okay, a saturated sound output is caused by a damaged speaker, replace it with a new one. 2. Clean the speaker terminal contact pads, make sure it is free from dust, corrosion and oxidation. 3. Check or replace the filter capacitors and filter coils. 4. For the right channel speaker not working, see to it that UI flex cable is not damaged, replace it as well if damaged. If the UI flex cable is okay, check both filter coils and capacitors. 5. If the both speakers,fil...