ACP Amana ACE14 / MCE14 Oven Error 4: High-Voltage Board

What does ACP Amana error 4 mean?

Error 4 involves the same part as Error 3, the high-voltage board that feeds the magnetron and the heater, yet the control reports it as a different number. That tells a technician the control found the failure in a different internal check, not in the same one that raises Error 3. The oven cannot cook until the board is repaired. The manual lists a high-voltage board that tripped a different internal check, a scorched plug on the magnetron supply from the board, a loose display board link that disturbs the board's signal, and a failed heater feed on the board. The maker's owner step is to disconnect power for one minute, plug the oven in again and test it. Write down whether Error 4 appears right at start-up or after a program begins, because the timing helps separate a board that fails at once from one that fails when loaded. If it returns, keep the oven off and call us. The board carries high voltage and is technician-only; it is not a job for an owner.

Affected models and control systems

This applies to the Amana ACE14 and MCE14 touch pad speed-cook ovens, as covered in the ACP Commercial Service and Training Manual. The numbered errors on these ovens are not shared with the AXP20/AXP22 families.

Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.

What you may notice

• Error 4 on the display
• The oven will not cook
• The error appears at start-up or once a program begins
• Error 4 returns after a one-minute unplug

Possible causes

Listed in ACP Amana's documentation

• High-voltage board tripped a different internal check
• Plug on the magnetron supply scorched
• Display board link loose, disturbing the board signal
• Heater feed on the high-voltage board failed

Other likely causes — what usually sits behind error 4 on this control. A technician confirms which one it is before any part is replaced.

• A plug on the magnetron supply with scorch marks that adds resistance and trips the board's own monitoring
• A display board link that has loosened and corrupts the control signal to the board

Safe checks before calling for service

How a technician diagnoses error 4

1. Read the error and note when it appears.
2. Discharge the oven properly and inspect the high-voltage board and plugs for scorching.
3. Check the display board link to the board.
4. Test the heater feed and magnetron supply outputs.
5. Replace the board or connector that fails its test.

How error 4 differs from similar codes

Error 3 on the same oven names the high-voltage board too. The two numbers mean the control found the failure by different checks.

Technical reference

Document

ACP Commercial Service and Training Manual

Edition

October 2012, 16400018

Models / control

ACE14 / MCE14 (touch pad speed-cook oven)

Section

Display Diagnostics - Error Codes, printed p. 33 (PDF p. 60)

Checked

October 2026

We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.