printer just won't power on at all, no lights, no sound, checked the outlet and it's fine.

Diagnosis

The total absence of power—no standby light, no fan noise, and no display activity—on a Canon imageClass LBP236dw typically indicates a complete break in the electrical circuit before it reaches the logic board. While a dead wall outlet is the most common culprit, since you have verified the outlet is active, the failure is likely occurring at the AC inlet, the internal power supply unit (PSU), or the main power fuse. In many cases, the LBP236dw experiences "power surges" that trip the internal thermal fuse or blow the primary capacitor within the PSU to protect the formatter board from frying. This happens most frequently if the printer is plugged into a low-quality surge protector or a daisy-chained power strip that cannot handle the high instantaneous current draw required by the fuser unit during the initial boot sequence. To confirm the failure is internal, check if the power cable feels unusually hot to the touch or if there is a faint scent of ozone or burnt plastic emanating from the rear ventilation slats.

How to Fix It

Since the external outlet is functional, you must isolate the failure point between the plug and the motherboard. Follow these steps precisely:

1. Unplug the power cord from both the wall and the printer. Inspect the prongs of the power cable for any signs of pitting, carbon buildup, or bending.
2. Locate a known-working "Kettle Lead" (IEC C13) cable from another device, such as a desktop PC or monitor. Plug this into the LBP236dw to rule out a break in the internal wiring of the original power cord.
3. Inspect the power socket on the rear of the printer. Ensure the pins are not pushed inward or bent. Firmly push the cable in until you hear or feel a definitive click; a loose connection here often mimics a dead PSU.
4. Perform a "Hard Power Reset": Unplug the printer and hold the power button down for 30 full seconds. This discharges the remaining electricity from the capacitors on the logic board. Leave it unplugged for 10 minutes, then plug it directly into a wall outlet (bypassing all surge protectors) and attempt to power on.
5. If the unit remains dead, the internal PSU (Power Supply Unit) has likely failed. This requires opening the chassis to test the DC output voltage using a multimeter. If you see 0V coming from the PSU to the main board, the PSU board must be replaced.

If That Didn't Work

• Check the internal fuse. If you are comfortable opening the casing, locate the primary fuse on the power board. Use a multimeter to check for continuity. If the fuse is blown (open circuit), replace it with an identical amperage fuse. However, be aware that fuses usually blow because of a short-circuit elsewhere; replacing the fuse may result in it blowing again immediately.
• Inspect the Power Switch assembly. The physical toggle/button on the LBP236dw can occasionally fail or become disconnected from the board. Check the ribbon cable connecting the power button to the main formatter board to ensure it hasn't vibrated loose during transport or heavy use.
• Test the "Eco" or "Sleep" state. In rare instances, the printer isn't "off" but is stuck in a deep sleep state where the display fails to wake. Try pressing the "Stop" or "Reset" button firmly while the printer is plugged in to see if the display flickers.
• Replace the Main Formatter Board. If the PSU is outputting the correct voltage but the printer remains lifeless, the logic board has suffered a catastrophic failure. This is the most expensive repair and often warrants replacing the entire unit.

Heads Up

• Avoid using "daisy-chained" power strips. Laser printers draw a massive amount of current to heat the fuser roller; using a thin extension cord can cause voltage drops that trigger a shutdown or damage the PSU over time.
• Always use a high-quality surge protector with a Joules rating of at least 1000J to prevent the internal fuses from blowing during electrical storms.
• Warning: Never open the printer casing while it is plugged in. The PSU contains high-voltage capacitors that can hold a lethal charge even after the device is unplugged.
• If you replace the PSU, ensure you use a genuine Canon part. Third-party power boards often have incorrect voltage tolerances that can permanently damage the image drum or fuser assembly.