TLDR;
- Fix: Replacement of missing electrical fuse
- Tools: Screwdriver, multimeter, soldering iron + wire, wire clippers
- Parts consumed: Electrical fuse x 2
- Validation: Insect Killer able to emit light when powered on

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### Diagnostics

1. Attempted to power on Insect Killer — did not light up, did not cause power trip
a. NCV test not conducted as plug doesn’t contain fuse
2. After unplugging, plastic casing was taken apart to inspect bulb and cylinder inside.
a. Output voltage of 1kV~1.5kV indicated on circuit board (probably involve the 5 yellow boxy components to perform voltage doubling).
b. No visible thermal fuse
c. Missing electrical fuse with wire legs remaining in position (1A 250V) ⚠️
i. Continuity test performed on plug pin and pin pressed into brown wire to check that brown wire connection to plug is OK ✅
ii. Continuity test performed on pin pressed into brown wire and headless wire legs to check that (1) brown wire is live wire and (2) connection to one leg is OK ✅

⇒ Likely cause of failure to power on appliance is a blown fuse

### Repair

1. Missing fuse’s wire legs de-soldered with soldering iron and suction device
2. New electrical fuse with same rating (probably? provided by senior coach but I should have recorded the rating) found. Body of fuse seems to be much larger than original.
3. Difficulty encountered cutting off the right length of excess fuse wire
a. After insertion of new fuse’s legs through where the old ones were, it was removed so the estimated excess length could be snipped off more comfortably with wire cutters.
b. Too much length was snipped off, making repositioning the fuse difficult. New fuse needed to be used, and excess was snipped off while fuse was held in place instead 🤓
4. New fuse’s legs soldered in place
5. Because of high voltage of appliance, advised to reassemble casing before testing
6. Brush was used to clean off any insect remains in the cylinder
7. After putting all parts back in place, appliance was powered on and managed to light up

⇒ Tube light not blown
⇒ Blown fuse likely sole cause of power trip

### Theory of Cause

Appliance consists of an inner column of metal poles that extended across vertically from alternating directions (top to bottom, bottom to top, etc.). Like 2 combs with interlocked teeth that don’t touch each other.

Inferred mechanics: the device works by forming a closed circuit when an insect comes into contact with adjacent poles.

A large bee (amongst other tiny insects) was found dead before repair. This might have caused a large current to pass through the device when it contacted multiple poles in the cylinder (lower resistance than smaller insect), leading to the blown fuse and local power trip.

Repaired during IHC session on 15 June 2025.

Summary
- Fix: Replacement of missing electrical fuse
- Tools: Screwdriver, multimeter, soldering iron + wire, wire clippers
- Parts consumed: Electrical fuse x 2
- Validation: Insect Killer able to emit light when powered on