Error Returns After Every Reset: Corroded Wire Connection

An error clears on reset and comes straight back. What returns after every reset is a connection, not a dead part.

By Team Snowflake | Updated 24 Aug 2026

Teaching case based on recurring Snowflake service patterns; identifying details are combined.

How this presents

An error code appearing, clearing on a power cycle, and returning sooner each time until the resets stop buying a full day. Nothing else about the system has changed, and it runs normally in the windows between.

Setup: LG Wall-mounted10-12 yearsHDBAng Mo Kio
Misread as: A failed outdoor control board, and the spend that comes with replacing one.
Check first: The outdoor wire connections, before any board is considered

What else produces this

A communication fault between indoor and outdoor units has two homes: the ends that generate and read the signal, or the path between them. A board that has failed stays failed. A path that is marginal works when it is nudged, which is what a power cycle does. Returning-after-reset is therefore a wiring pattern, and wiring is the cheaper half to clear.

A cable testing continuous end to end takes the run itself out of the question.
Green corrosion on a connector at the outdoor unit shows up on sight, with nothing needed to detect it.
A connector holding its wire loosely enough to move by hand will interrupt a signal a sound one carries.
Every other connection sound and tight contains the fault to one point, which is what makes the repair small.

Why it happens

Outdoor connections sit in heat and humidity for years, and moisture works into a contact until corrosion eats the metal that was doing the carrying. The signal between indoor and outdoor units is small, so it fails at a contact long before mains power would. Once the contact drops, the code appears. A power cycle disturbs the joint enough to remake it briefly, which is why the fault comes and goes rather than settling.

What resolution involves

Strip the cable back to clean copper, fit a new connector, and protect the joint against the air that corroded the last one. No board work follows. The part worth carrying forward is the inspection habit: the same exposure that took one connector is working on its neighbours, so outdoor connections belong on the servicing list rather than in the next fault report.

How to tell it worked

The code staying gone through a week of ordinary running, not through the afternoon of the visit. A connection repair proves itself over days, because the fault it replaces was intermittent to begin with.

Before you approve a quote

A fault that clears on a restart is a contact, not a corpse

Dead parts do not recover on a power cycle. Recovery means something is dropping in and out.
Ask whether the outdoor connections were inspected before a board is quoted. Corrosion there is visible, not measured.
A connector that corroded once has neighbours in the same air. Ask for them to be checked at the next service.

Questions this case answers

Why does an LG CH05 error clear when the aircon is switched off and on?

Because the fault is a contact that is marginal rather than a part that has died. Powering down and up disturbs the joint enough to remake it for a while. A board that had genuinely failed would show the same code again immediately, which is the useful difference between the two.

Is CH05 always a control board problem?

No, and the reset behaviour is what separates them. The code only says the two halves have lost their signal. It says nothing about whether the cause is the board that sends it, the board that reads it, or the connection carrying it between them.

What causes green crust on the aircon wires outside?

Corrosion. Moisture works into the contact over years of heat and humidity, and eats the metal doing the carrying. The signal between the two units is small enough to fail at a corroded contact long before mains power would notice.

How do I stop outdoor wire connections corroding again?

Clean metal, a fresh connector and a protective grease over the joint slow it considerably. Nothing stops it outright in this climate, which is why outdoor connections are worth a look during servicing rather than at the next breakdown.

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Tell us what’s going on. Symptoms, setup, photos, anything we should know. We’ll assess and come back with the right next step.

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