Repair guides
Pick a type, an appliance or a brand. Every guide lists the tools, the safety call-outs, the steps and the reading you should expect.
Diagnostic · 374
Symptom → most likely cause, step by step
Component tests · 69
How to test a specific part, with expected readings
Installation · 33
Install, replace and hook up appliances correctly
Fundamentals · 24
Core skills every appliance tech uses
Appliance
Brand-specific guides
5 guides for LG · Air Conditioners
Diagnostic · 5
Mini-split communication error: interconnect wiring check
Most communication faults are wiring: swapped terminals, loose screws, splices or damaged cable, often after a new install or a storm. Check power, then terminations at both ends, then the data signal, before replacing a board.
Mini-split indoor unit blinking light (reading the code)
A blinking pattern is a fault code. Count the blinks before you reset power, because a breaker reset erases the code. Then look it up for the brand and fix the cause.
Portable AC shows water-full code or keeps filling
In humid weather or dry mode, a portable can collect water faster than it evaporates it. Drain and set up a continuous drain first; a code with an empty tank points to the float switch or internal pump.
PTAC error codes: how to read and clear them
Most PTAC brands store fault codes that can be shown with a button combination on the control (for example GE Zoneline uses a MODE + another key sequence on some models). Read the active code, fix the cause, then clear it.
PTAC not cooling (fan runs, air not cold)
Most PTAC no-cool calls are airflow (filter, coils), a wrong control setting or a failed compressor start component. Rule those out before suspecting the sealed system.