July 14, 2025

LG Model LW8016ER Y7 in my shop

This is a window AC unit that I use to cool things off in my lab/workshop/office. Online it generally gets refered to as the LW8016ER, who knows what the trailing "Y7" on my model are about.

On July 14, 2025 I noticed that it was running full tilt. It was cold in my shop in the morning (68F), the AC was blowing cold air, and it was 76 outside (and soon to get much hotter).

The AC compressor is running full time, no matter what mode it is in and no matter what the temperature setpoint is. I can put it in "fan" mode and it still blows cold air. I measure the air coming out of the unit in fan mode as 48-50F.

My conclusion is that the relay that controls the compressor has shorted. The control panel acts totally fine.

How to fix it

The front panel board is logic only. There is a power board inside the unit that has the relay. It will be necessary to pull the unit out of the wall to remove the power board.

The power board is part EBR83604002 and I see it selling for $80.

The following video shows how to remove and fix the power board. He uses an OMRON G4A-1A-E DC12 relay from Digikey. The part costs $7.80 at Digikey and they have 21,628 of them in stock.

The original relay is a SANYOU SFK-112Dm-GW. You can find these on Ebay and even on Amazon it turns out -- but I ordered the OMRON part.

The part arrived from Digikey and I installed it the next day (7-19-2025). This worked great and fixed it! The bulk of the work is getting the unit out of and back into the wall.

Useless details

The controller chip is labeled R5F100FEA 1708KME04. This is a controller made by Renesas. It has a RL78 CPU core (CISC), from 16 to 512K of flash, 4 or 8K of ram.

Alongside of this is a STLED316 chip, which is a 6 digit LED controller with keyscan. Maybe this drives the 7 segment display showing the temperature setpoint.

Have any comments? Questions? Drop me a line!

Tom's Home repair pages / tom@mmto.org