GE Microwave Probe Error: Troubleshooting Why Probe Must... | appliancefaults.com

Technical Background:

GE microwaves use a temperature probe to monitor the internal temperature of food during cooking. The MCU sends a low voltage signal (typically 5V DC) to the probe receptacle. The probe contains a thermistor, which changes resistance based on temperature. The MCU reads the voltage drop across the thermistor to determine the food's temperature. If the MCU detects an open or short circuit in the probe circuit, it will display a “Probe Error”.

Symptoms:

The microwave displays a “Probe Error” message and will not start the temperature cooking cycle. The oven may still operate in regular microwave mode, but temperature sensing is disabled.

Possible Causes:

Faulty temperature probe.
Damaged probe receptacle.
Open circuit in the probe wiring harness.
Defective MCU (Main Control Unit).
Improper probe insertion.

Solution:

1

Unplug the microwave from the 120V AC outlet.
2

Inspect the temperature probe for any signs of damage, such as frayed wires or a bent tip.
3

Check the probe receptacle inside the microwave for loose connections or corrosion. Clean with a small brush if needed.
4

Using a multimeter, test the continuity of the temperature probe. A typical resistance value should be between 1k and 10k ohms depending on the probe type. An open circuit indicates a faulty probe.
5

Trace the probe wiring harness back to the MCU. Look for any breaks or shorts in the wiring. Repair or replace as needed.
6

If the wiring and probe are good, the MCU may be faulty. Replacement may be required. Consult the service manual for specific MCU testing procedures.
7

Ensure the probe is fully inserted into the food and the receptacle during temperature cooking.

Safety Warning:

Disconnect the microwave from the power supply before performing any repairs. Microwaves contain high voltage components that can cause serious injury or death. Always discharge the capacitor before working on the internal components. Use proper Lock-Out/Tag-Out (LOTO) procedures.

Prevention:

Regularly inspect the temperature probe for damage. Avoid bending or twisting the probe cable excessively. Clean the probe and receptacle after each use to prevent corrosion. Store the probe safely when not in use.

Expert Tip:

Some GE microwave models have a service mode that allows you to test the temperature probe circuit. Consult the service manual for the specific procedure to enter service mode and run the probe diagnostic test.

Frequently Asked Questions

•What is the typical resistance range for a GE microwave temperature probe?

The resistance typically falls between 1k and 10k ohms at room temperature, but always refer to the service manual for the specific model.

•How do I discharge the capacitor in a GE microwave before working on it?

Use an insulated screwdriver with a 10k ohm resistor inline to short the capacitor terminals. Verify with a multimeter that the voltage is near 0V DC.

•Where can I find the service manual for my GE microwave model?

You can often find the service manual online through appliance parts retailers or by searching the model number followed by "service manual".

GE Microwave Probe Error: Troubleshooting Why Probe Must Be Inserted

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance range for a GE microwave temperature probe?

•How do I discharge the capacitor in a GE microwave before working on it?

•Where can I find the service manual for my GE microwave model?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: