Genuine LiftMaster K76-34728 EMI board — the AC input board in the CSL24 slide and CSW24 swing gate operators. It carries the 120 V receptacles, the AC power switch and the EMI filtering between the incoming mains and the transformer. It is not a control board, and it does not change between the V, VDC and U generations.
When it is the fault. The operator is completely dead: no lights on the main board, no output from the transformer, with 120 V confirmed at the operator. The EMI board, the K204C0211 toroid transformer and the K52C0481 bridge rectifier are the three parts between the mains and the main board; a surge usually takes one of them before it reaches the board.
Specifications
| Part number | K76-34728 |
|---|---|
| LiftMaster description | EMI Board with 120V Receptacles and AC Power Switch |
| Fits | CSL24U, CSL24UL, CSL24V, CSL24VH, CSL24VDC and CSW24U, CSW24UL, CSW24V, CSW24VH, CSW24VDC |
| Condition | Genuine LiftMaster OEM, new |
Dead operator — what to check, in order
| Check | Part |
|---|---|
| 120 V at the operator terminals | Breaker and site wiring — nothing to buy yet |
| AC power switch and receptacles | This board, K76-34728 |
| Transformer output | K204C0211 toroid transformer |
| DC after the rectifier | K52C0481 bridge rectifier |
| Main board | K1D8389-1CC (U/UL), K1D8059-1CC (VDC) or K1D6597-1CC (V) |
Fit surge protection at the same time. Storm damage is a leading cause of gate operator board failure. If this board died after a storm, the replacement is at the same risk unless the installation is protected.
Related
Not sure which board you need? Send a photo of your existing board to parts@gatehousesupplies.com or call 866-965-5599. We install and service these operators and would rather confirm it than have you fit the wrong board. Since 1993.
