中文
含义
F4 表示微波炉第二湿度传感器故障，仅出现在配备双湿度传感器的高端机型中（如 GE Profile 系列）。双传感器系统中，传感器 1 检测排气湿度，传感器 2 检测腔体内湿度，两者配合实现更精准的自动烹饪控制。F4 对应传感器 2 的信号异常（开路或短路），故障影响与 F3 类似——传感器自动烹饪模式将不可用，但手动定时加热功能不受影响。
常见原因
- 传感器 2 探头（位于腔体内壁排气口附近）被食物飞溅物覆盖，湿敏表面失效。
- 传感器 2 内部元件因腔体内高温辐射老化损坏。
- 传感器 2 信号线束在腔体后部走线时受到机械挤压，内部导线断裂。
- 连接传感器 2 的控制板端子松动或冷焊。
- 传感器 2 信号调理电路独立于传感器 1，该通道的运放或 ADC 输入损坏。
自助排查
- 检查微波炉腔体内部侧壁或顶部通风口附近是否有独立的传感器探头（与排气传感器位置不同）。清洁腔体内部的食物残渣和油污。
- 拔掉微波炉电源。找到传感器 2 在控制板上的独立插头（通常标有 SENSOR2 或 HUM2），拔下后用万用表测量传感器引脚阻值，与传感器 1 对比。两者阻值应接近，若偏差超过 50% 则传感器 2 已损坏。
- 目视检查传感器 2 线束从腔体到控制板的整段路径，查看是否有被金属边缘挤压或割伤的位置。
- 重新插紧传感器 2 插头，通电测试。如果故障变为 F3（传感器 1 故障），说明插头此前位置错误，将两个传感器插头互换回正确位置即可。
- 若传感器 2 本身正常，联系 GE 售后诊断控制板传感器 2 通道。高端双传感器型号的维修建议由专业人员执行，以免损坏校准数据。
English
Meaning
F4 indicates a fault with the microwave’s second humidity sensor, found only on premium models equipped with dual humidity sensors (e.g., GE Profile series). In a dual-sensor system, Sensor 1 detects exhaust humidity and Sensor 2 detects cavity humidity; together they enable more precise automatic cooking control. F4 corresponds to an abnormal signal (open or short) from Sensor 2. The impact is similar to F3 — sensor-based automatic cooking modes become unavailable, but manual timed heating continues to work.
Common Causes
- The Sensor 2 probe (located near the exhaust port on the inner cavity wall) is coated with food splatter, rendering the humidity-sensitive surface inactive.
- The internal element of Sensor 2 has aged and degraded from exposure to radiant heat inside the cavity.
- The Sensor 2 signal harness is mechanically pinched along its routing at the rear of the cavity, causing internal conductor breakage.
- The control board terminal for Sensor 2 is loose or has a cold solder joint.
- Sensor 2 has a dedicated signal conditioning circuit independent of Sensor 1, and that channel’s op-amp or ADC input is damaged.
Self-Check Steps
- Inspect the interior of the microwave cavity, particularly the side wall or top vent area, for a separate sensor probe (different from the exhaust sensor location). Clean any food residue and grease from the cavity interior.
- Unplug the microwave. Locate the separate connector for Sensor 2 on the control board (typically labeled SENSOR2 or HUM2). Unplug and measure the resistance across the sensor pins with a multimeter, comparing with Sensor 1. The two should have similar resistance values; a deviation greater than 50% indicates Sensor 2 is damaged.
- Visually trace the entire Sensor 2 harness from the cavity to the control board, looking for areas where it may be pinched or cut by metal edges.
- Reconnect the Sensor 2 plug firmly and test with power. If the fault changes to F3 (Sensor 1 fault), the connectors were previously swapped — exchange the two sensor plugs back to their correct positions.
- If Sensor 2 itself is normal, contact GE service to diagnose the Sensor 2 channel on the control board. Repairs on premium dual-sensor models are best performed by professionals to avoid damaging calibration data.