Speed Queen Washer Error Code Eio 39: Mosfet Cannot Be Disabled
Eio 39 means the Mosfet enable on a CHM1792C washer-extractor's input and output board cannot be turned off: the control asked for it to switch off and the line stayed on. A stuck-on enable is a safety concern, so the machine stops. Write down the code, wait for the lock, and ask us for a visit without opening the cabinet.
High: outputs might stay powered, and the machine stays stopped until the cause is fixed.
- Code
- Eio 39
- Maker
- Speed Queen
- Equipment
- Washers
- Applies to
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
What does Speed Queen error code Eio 39 mean?
The enable line is the master gate for the input and output board's outputs. When a cycle ends or the control needs to shut everything down, it commands the enable off and then checks that the line actually went off. Eio 39 means the control asked the board to switch the enable line off and the line stayed on. That is a safety concern, because outputs might stay powered when they should not, so the control stops the machine and holds the code on the display. It is the mirror image of Eio 38, where the line would not come on. The manual lists a Mosfet enable circuit stuck on at the board, a control signal to the board that does not switch it off, and a board supply problem that holds the enable line high. Because outputs could remain live, this is the one Eio code where cutting power at the main disconnect is sensible if you know where it is.
Affected models and control systems
CHM1792C family washer-extractors, QN models, 20 to 100 lb, with the front-end control and its input and output board.
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
- Eio 39 shows after a cycle ends or at shutdown
- The machine stops and will not restart
- Outputs may seem to stay active
Possible causes
Listed in Speed Queen's documentation
- A Mosfet enable circuit stuck on at the board
- A control signal to the board that does not switch it off
- A board supply problem that holds the enable line high
Other likely causes — what usually sits behind error code Eio 39 on this control. A technician confirms which one it is before any part is replaced.
- A Mosfet that has failed shorted after a surge and now conducts all the time
- A board contaminated with moisture so the enable line leaks high
Safe checks before calling for service
- Write down the whole code.
- Wait until the door lock releases.
- If you know where the machine's main disconnect is, switch it off and leave a sign on it.
- Do not open the cabinet; ask us for a visit.
How a technician diagnoses error code Eio 39
- Read the full code and note whether the enable line is high with the control commanding it off.
- Check the board for moisture, corrosion or heat damage, with power off and locked out.
- Measure the board supply and the control signal to the enable line.
- Confirm whether any output stays powered when it should not.
- Replace the board or control only after the signal test.
- Outputs that cannot be switched off may stay live, which makes opening the cabinet unsafe.
- A stuck-on Mosfet usually means the board needs replacing, which is work on 208-240 V equipment.
- The test separates a bad control signal from a shorted board and needs a meter.
How error code Eio 39 differs from similar codes
Eio 39 is an enable that cannot be turned off. Eio 38 is the one that cannot be turned on.
Technical reference
- Document
- Washer-Extractor Programming CHM1792C_SVG, Part No. F8641001ENR4, Error Codes Table 29 (pp. 100-107)
- Edition
- Part No. F8641001ENR4, January 2020
- Models / control
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
- Section
- Error Codes, Table 29, pp. 100-108 (PDF pages equal printed pages)
- 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.
Related Speed Queen washer error codes
Why is Eio 39 a safety concern?
Outputs might stay powered when they should not, so the control stops the machine.
Should I switch off the main disconnect?
If you know where it is, yes, and leave a sign on it. Do not open the cabinet.
Is Eio 39 the same as Eio 38?
No. Eio 38 means the enable will not turn on; Eio 39 means it will not turn off.
Need help with Speed Queen error code Eio 39?
A technician confirms the cause on site and gives you the price in writing before any work starts.