6871A20912J Genuine Sub PCB Assembly for LG Air Conditioners, LG Air Con Secondary Circuit Board, PCB Assy Sub

6871A20912J is a genuine LG sub PCB assembly, which we list for LG air conditioners. LG uses the term sub PCB for a secondary circuit board that works alongside the main board, for example to look after a display, a signal receiver or a group of outputs. No models are on file, so compare the number on your old board's label before ordering.

When an LG air con sub board fails

A failed sub board usually causes a fault in whatever it controls rather than a completely dead unit. Depending on its job, you might see a blank or garbled display, a unit that ignores the remote, louvres or fans that don't respond, or an error code pointing to communication between boards. Power surges, moisture and insects are common causes. Look for burn marks, corrosion or damaged tracks, and check the connectors between boards are seated before replacing anything.

Part details

• Genuine LG part 6871A20912J
• Sub PCB assembly
• Listed for LG air conditioners
• Check the number on the old board before ordering

Replacing the sub PCB

Switch the unit off and isolate it at the switchboard, then wait a few minutes for any stored charge on the boards to drain. Air conditioners are hard-wired and should be worked on by a licensed electrician or air conditioning technician. Handle the board by its edges, photograph every plug, and secure the board in its housing before restoring power.

Questions about this part

How do I know the sub board is the problem?

A technician will check the fault code, the connections between boards and the parts the board controls. If those check out and the board shows damage or fails testing, replacing it is the fix. Guessing gets expensive with electronic parts.