Question 1

the convection bake or roast function doesn't seem to get hot enough, food takes forever to cook.

Accepted Answer

DIAGNOSIS The quartz heating element is failing or the temperature sensor (thermistor) is giving a false reading to the control board. FIX Run a convection cycle at 400°F for 10 minutes. Carefully observe through the window. The heating element at the top rear of the cavity should glow bright orange consistently. If it's dim, cycles on/off rapidly, or doesn't glow, the element is faulty and needs replacement. IF THAT DIDN'T WORK If the element glows properly, the cavity temperature sensor is likely out of calibration or faulty. This requires a technician with the correct tools to diagnose and replace. HEADS UP The interior light may stay off during a convection-only cycle. This is normal. Do not open the door frequently to check the element, as this causes large temperature swings and extends cooking time.

Question 2

my sharp microwave starts but then stops after a few seconds, like it loses power, but the clock stays on.

Accepted Answer

DIAGNOSIS This is a thermal cutoff. The unit is overheating and shutting down to protect itself. The most common cause is a blocked or failed ventilation system. FIX Unplug the microwave. Pull it away from the wall. Vacuum the rear grill and the top vent (if over-the-range) thoroughly. Check that the internal magnetron cooling fan is running when the unit is on. If the fan is not spinning, it or its motor needs replacement. IF THAT DIDN'T WORK The thermal cut-off fuse or the magnetron thermal protector may be failing intermittently. These are located on the magnetron or air duct and require a multimeter to test when hot. HEADS UP Operating with blocked vents can permanently damage the magnetron. Ensure at least 3 inches of clearance on all sides, especially the top and rear.

Question 3

the clock on my sharp microwave resets to 0:00 every time i unplug it or have a brief power flicker.

Accepted Answer

DIAGNOSIS The Sharp SMC1585BS relies on a volatile memory system powered by a small capacitor or backup battery on the main control board to maintain the clock and user preferences during power interruptions. If the clock resets to 0:00 after a brief flicker or unplugging, the memory backup circuit has failed. Because this component cannot hold a charge, the board loses its "state" the moment current is interrupted, forcing a hard reset of the system clock. FIX Because the backup capacitor is integrated and soldered directly to the main control board, it cannot be swapped individually. The only permanent solution is to replace the entire main control board. Disconnect the microwave from the wall outlet to ensure no power is flowing to the unit. Remove the outer chassis screws to access the internal components. Locate the main control board (the PCB connected to the front display panel). Disconnect the wiring harnesses carefully, noting their positions. Unscrew the board from the chassis and install a compatible replacement board. Reconnect the harnesses and reassemble the chassis. IF THAT DIDN'T WORK If a new board still fails to retain the time, check for an unstable power supply in your kitchen. Severe voltage drops or "brownouts" can sometimes bypass the backup circuit's ability to maintain memory. In this case, plugging the unit into a high-quality surge protector or a small UPS (Uninterruptible Power Supply) can prevent the clock from resetting during minor flickers. HEADS UP Warning: Microwaves contain high-voltage capacitors that can hold a lethal electrical charge even when the unit is unplugged. Do not touch the capacitor or the high-voltage transformer area unless you are trained in discharging these components. If you are uncomfortable with high-voltage electronics, contact a certified technician for the board replacement.

Question 4

how do i clean the inside roof of my sharp convection microwave? it's got baked-on grease from convection cooking.

Accepted Answer

DIAGNOSIS Grease and food splatter polymerize onto the enamel surface during high-heat convection cycles, making it hard to remove. FIX Use a dedicated microwave cleaner or make a paste of baking soda and water. Apply it to the soiled area on the ceiling. Let it sit for 15 minutes. Use a non-abrasive sponge or cloth dampened with very hot water to scrub. The grease should lift. Wipe clean. IF THAT DIDN'T WORK For stubborn spots, use a very mild degreaser like diluted Simple Green. Spray on the cloth, not directly into the cavity, to avoid control panel damage. Wipe immediately and thoroughly. HEADS UP Never use steel wool, abrasive pads, or harsh oven cleaners. They will permanently damage the enamel coating and make future cleaning harder.

Question 5

the turntable in my sharp microwave won't spin at all, just sits there.

Accepted Answer

DIAGNOSIS When the turntable on a Sharp SMC1585BS fails to rotate, the issue typically stems from one of three failure points: mechanical obstruction, a stripped drive coupling, or a complete electrical failure of the synchronous motor. Because this model uses a high-torque convection system, the turntable is subject to more vibration than a standard microwave, which can lead to the glass tray shifting slightly off its center axis, causing the roller ring to jam. If the tray is seated correctly but still won't move, the most likely culprit is the drive coupling (the plastic D-shaped piece that connects the motor shaft to the roller ring). Over time, the plastic teeth on this coupling can strip or crack due to the weight of heavy convection-ready cookware. To confirm a motor failure versus a mechanical jam, listen closely during operation; if you hear a faint humming or clicking sound coming from the bottom of the unit but the tray remains stationary, the motor is attempting to engage but the coupling has failed. If there is total silence and no movement, the motor's internal windings have likely burnt out. FIX Follow these steps to isolate and repair the rotation assembly: Power Isolation: Unplug the microwave from the wall outlet completely. Do not rely on the "Stop" button, as the capacitor inside the unit can hold a dangerous charge, but the motor area is generally safe once unplugged. Tray Alignment Check: Remove the glass turntable tray and the plastic roller guide ring. Inspect the roller ring for any melted plastic or debris stuck in the wheels. Clean the floor of the microwave cavity with a damp cloth to remove any grease buildup that might be creating friction. Coupling Inspection: Look at the center of the microwave floor. You will see a plastic drive coupling protruding from the base. Rotate it gently by hand. If it spins freely without resistance or feels "loose" on the shaft, the coupling is stripped. Coupling Replacement: If the coupling is cracked, pull it straight up and off the motor shaft. Slide a new replacement coupling (ensure it is the exact part for the SMC series) onto the D-shaped shaft until it seats firmly. Motor Replacement: If the coupling is intact but the motor is dead, you must remove the outer cabinet screws. Locate the turntable motor mounted to the underside of the chassis. Disconnect the two spade connectors from the motor terminals. Unscrew the motor mounting bracket, remove the failed motor, and install a new synchronous motor. Reassembly: Reinstall the cabinet, place the roller guide ring back in the center, and set the glass tray specifically into the notches of the ring. Power on the unit and test with a light load. IF THAT DIDN'T WORK Check the Roller Ring Track: Inspect the groove in the bottom of the microwave cavity. If a small piece of food or a plastic shard has fallen into the recessed track where the roller ring sits, it can create enough friction to stall the motor. Use a toothpick or a vacuum to clear the perimeter of the floor. Verify the Glass Tray Fit: Ensure you are using the original Sharp glass tray. Third-party replacement trays that are slightly too heavy or have a different center-hole diameter can put excessive axial load on the motor shaft, causing it to trip its internal thermal protector and stop spinning. Inspect the Wiring Harness: If you have already replaced the motor and it still won't spin, check the wiring harness connecting the motor to the main control board. Look for signs of rodent damage or charred wires near the convection heating elements, as the heat from the convection fan can sometimes degrade the insulation of the motor wires. Test the Control Board Relay: In rare cases, the relay on the main PCB that sends power to the turntable motor fails. If you have a multimeter, test for voltage at the motor terminals during a cycle. If no voltage is present, the control board requires repair or replacement. HEADS UP Weight Limits: Avoid placing extremely heavy pots (over 10 lbs) on the turntable during convection mode, as this puts immense strain on the plastic coupling and can strip the gears instantly. Cleaning the Ring: Regularly remove the roller guide ring and wash it with soap and water. Grease buildup on the wheels is the leading cause of "stuttering" rotation. Avoid Forcing: Never manually force the turntable to spin rapidly by hand while the unit is off, as this can bend the motor shaft and cause permanent misalignment. Safety Warning: Always disconnect power before removing the outer casing. Microwave capacitors can store lethal voltages even when unplugged; avoid touching the high-voltage transformer or capacitor area.

Question 6

there's a loud humming or buzzing noise coming from the back of my sharp microwave, especially on convection bake.

Accepted Answer

DIAGNOSIS This is almost always the convection fan motor or its bearings failing. The motor is located in the rear cavity behind the microwave. FIX Unplug the microwave. Remove the outer casing. Locate the convection fan motor (attached to the metal air guide). Check for free spin. If it's grinding or seized, the motor assembly must be replaced. Ensure the fan blade isn't hitting anything. IF THAT DIDN'T WORK A failing magnetron can sometimes buzz, but that's rare during convection-only cycles. If the noise is only during microwave operation, suspect the magnetron or high voltage diode. HEADS UP The convection fan motor may share a mounting plate with the magnetron cooling fan. Label wires and take pictures before disassembly to ensure correct reassembly.

Question 7

i get an F1 error code on my sharp smc1585bs, it just flashes and won't heat anything.

Accepted Answer

DIAGNOSIS The F1 error code on the Sharp SMC1585BS is a critical safety lockout indicating a failure in the door interlock circuit. This convection microwave utilizes a series of three primary door switches (microswitches) that must trigger in a specific sequence to confirm the door is fully sealed before the magnetron can engage. If the control board detects that one switch is "closed" while another is "open" (an illegal state), it triggers the F1 code to prevent microwave radiation from leaking into the cabin. This failure typically occurs because the plastic door latch hook has worn down or snapped, preventing the switch from being fully depressed. Alternatively, the internal copper contacts within the microswitch have oxidized or carbonized due to repeated sparking (arcing), causing a loss of continuity. You can confirm this by observing the display; if the F1 code appears immediately upon closing the door or flashes the moment you press "Start," the circuit is broken. If the code appears only after a few seconds of operation, it is likely a thermal trip or a loose connection in the wiring harness. FIX To resolve the F1 error, you must identify and replace the faulty interlock switch. This requires a digital multimeter and basic hand tools. Power Down: Completely unplug the unit from the wall outlet. Warning: Microwaves contain high-voltage capacitors that can hold a lethal charge even when unplugged. Do not touch the large capacitor near the magnetron. Access the Chassis: Remove the outer cabinet screws and slide the cover off to expose the door frame and the switch assembly. Isolate the Switches: Locate the three microswitches mounted on the right-hand side of the door frame. These are typically small rectangular boxes with a metal lever and two or three spade terminals. Continuity Testing: Set your multimeter to the Continuity (Ohms) setting. Test each switch individually: Primary Switch: Should be "Open" when the door is open and "Closed" when the door is shut. Secondary/Monitor Switch: This is the safety switch. It must change state in the opposite direction of the primary. If it stays "Closed" regardless of door position, it is failed. Mechanical Check: Manually push the switch levers with a small screwdriver. If you do not hear a distinct "click" or if the lever feels mushy, the internal spring has failed. Replacement: Disconnect the spade connectors from the faulty switch. Install a matching microswitch (ensure the lever type—roller or plunger—matches exactly). Calibration: Close the door and ensure the latch hook is making full contact with the switch lever. If the hook is worn, file a small amount of material off the plastic housing to allow the hook to sit deeper. Test: Reassemble the chassis and plug the unit back in. The F1 code should now be cleared. IF THAT DIDN'T WORK Inspect the Door Latch Hook: Examine the plastic hook on the actual microwave door. If there is a hairline crack or the hook is bent, it will not exert enough pressure to trigger the switches, even if the switches themselves are brand new. Replace the door latch assembly if the plastic is deformed. Check the Wiring Harness: Inspect the thin-gauge wires leading from the switches to the main control board. Because the door is opened and closed thousands of times, wires can fray or pull out of the spade connectors. Gently tug each wire to ensure they are seated firmly. Control Board Relay Failure: If all switches test positive for continuity but the F1 code persists, the relay on the main PCB (Printed Circuit Board) that monitors the door circuit may have failed. Look for burnt solder joints or "blown" capacitors near the door logic section of the board. Reset the Logic: Perform a hard reset by unplugging the unit for at least 30 minutes. This clears the volatile memory of the control board and can sometimes clear a "ghost" F1 error caused by a power surge. HEADS UP High Voltage Warning: Never touch the high-voltage capacitor (the large silver cylinder) without properly discharging it using an insulated screwdriver. This component can store 2,000+ volts even after the unit is unplugged. Avoid Generic Switches: Only use high-temperature rated microswitches. Cheap generic switches can melt under the heat generated by the convection fan, leading to a repeat F1 failure within weeks. Clean the Latches: Use a cotton swab with isopropyl alcohol to clean the door hooks and switch levers. Grease and food residue buildup can prevent the door from seating fully, triggering the safety lockout. Door Alignment: If you have recently moved the microwave, ensure it is on a perfectly level surface. A tilted chassis can cause the door to misalign by a few millimeters, which is enough to trigger an F1 error.

Question 8

my sharp convection microwave won't start, the clock is on but nothing happens when i press any buttons, it just beeps.

Accepted Answer

DIAGNOSIS The control board is getting power but the touchpad is not registering presses. A failed membrane switch panel or a loose ribbon cable connection is the most common cause. FIX Unplug the microwave. Remove the outer case. Locate the flat ribbon cable connecting the control panel to the main control board. Disconnect and firmly reseat this cable at both ends. Reassemble and test. If that fails, the entire membrane switch panel needs replacement. IF THAT DIDN'T WORK The main control board itself may have failed. Check for any visible burnt components or cracked solder joints on the board. Board replacement is the only fix. HEADS UP High voltage capacitors inside can hold a lethal charge even when unplugged. If you are not comfortable, do not open the case. Call a technician.

Sharp SMC1585BS Convection Microwave

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