Handheld Megaphone Speaker From School
Received 2 units of Handheld Megaphone Speakers from a primary school. Provided free debugging and free repair service to the school.
Symptoms:
- Upon power on, there is no sound output
Analysis:
- Checked the battery, it is using a customised Battery Pack (18650 Li-Ion, single cell, 3.7V, 2000mA)
- Battery pack comes with USB port for charging, but unable to charge when insert to a USB port for charging.
Photos:
- Unlatch and open up the back cover of Megaphone
- Unplug the battery pack from USB Port
- Unscrew a screw at the battery pack housing
- Take out the old 18650 Battery
- Disconnect the old 18650 Battery from +/- terminal wiring (spot welded)
- Prepare 2pcs of Nickel strip to make 2 plates for +/- terminal wiring spot welding
- Clamp the nickel plates onto +/- terminal wiring using wire cutter
- Spot welding a nickel plate onto the new 18650 Battery positive (+) terminal
- Spot welding a nickel plate onto the new 18650 Battery negative (-) terminal
- Reinsert the new 18650 Battery into its housing
- Screw the housing and turn on the switch to check Battery Pack. The Red LED is on upon switched on, means battery is fine. Take the Battery Pack for USB charging, charge until LED turn to Blue colour.
Tools Involved:
- Multimeter
- Screwdriver Set
- Wire cutter
- Spot Welder
- Tweezers
- Scissor
Cost Involved:
- 18650 Li-Ion Battery (4800mA): US$0.80
