Warning: Disconnect power before servicing.
ErrBase

RCA Microwave Troubleshooting: Common Problems

Quick Answer

Most RCA microwave issues involve a blown ceramic fuse, faulty door interlock switches, or a failing high-voltage diode. If the unit has power but won't start, the door switches are the most likely culprit. If it runs but doesn't get hot, you are usually looking at a failed magnetron or diode.

Nine times out of ten when I get called about an RCA microwave, it's a door switch. Ignore it long enough and the monitor switch will eventually blow the main fuse to protect the circuit, and now you've got two problems. The high-voltage stuff, don't mess with it unless you know what you're doing. A blown capacitor at 2100 volts isn't a mistake you make twice.

RcaMicrowaveSeverity: moderate
Time to Fix
15–60 min
Difficulty
beginner
Parts Cost
—
Tools Needed
Phillips #2 screwdriver, Flat-head screwdriver

What Does the PROBLEMS Code Mean?

OK so RCA builds these things to a price point, which basically means simpler components with fewer redundancies. That's not always bad. Simple means fixable. Most problems I've seen with these units cost under $20 to fix, usually a fuse or a door switch. But if the magnetron's gone, honestly just buy a new one. Parts alone can hit $80-100 on a $60 microwave.

Common Causes

  • One of the three door interlock switches has a broken actuator, which means the control board never gets the 'safe to run' signal and the unit just sits there doing nothing when you press Start.
  • The 20-amp ceramic fuse on the main board blew, usually because someone opened the door mid-cycle or a door switch failed and triggered the monitor switch to do its job.
  • The high-voltage diode shorted out, which kills the magnetron's ability to generate heat. You'll often smell something burnt around the bottom of the cavity when this happens.
  • Magnetron tube failed after years of heavy use. Budget units that get run multiple times a day tend to hit this point around the 7-10 year mark.
  • Stripped turntable drive coupling on the motor, pretty common on RCA units because the plastic they use on that little coupler is on the softer side.
  • Loose wiring connector on the main control board from vibration, since the lightweight cabinet transfers a surprising amount of movement to the PCB mounts over time.

Symptoms You May Notice

  • You start a cycle and hear the fan and light come on, but the food is stone cold two minutes later.
  • Completely dead, no clock, no display, nothing at all, like it's not plugged in even though it is.
  • The turntable plate just sits there not spinning and you're getting a hot spot in the center with cold edges on everything.
  • There's a loud, angry hum or buzzing noise during the cook cycle that definitely wasn't there six months ago.
  • Sparks or little flashes of light inside the cabinet, usually near the side wall where that cardboard-looking cover is.

Can you reset a Rca microwave to clear the PROBLEMS code?

Unplug the microwave from the wall completely. Don't just flip a breaker, actually pull the plug. Wait a full 60 seconds so the capacitors on the control board can discharge and clear any lockout state. Plug it back in and you should see the clock display prompt blinking. If the keypad is still locked and nothing responds, try holding the Stop/Cancel button for 3-5 seconds right after power-up. That clears child lock on most RCA models.

Tools Required for Diagnosis

Phillips #2 screwdriverFlat-head screwdriverDigital multimeterInsulated needle-nose pliersReplacement 20A ceramic fuse (5x20mm)Discharge resistor (10k ohm, 10W with insulated leads)Safety glassesWork gloves

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

ComponentComponent Under Test
Expected Range0–2 ohms
ConditionIf Open (OL) or infinite, replace component.

Frequently Asked Questions

Why is my RCA microwave sparking inside?
Sparking is almost always the waveguide cover, that square panel on the side wall inside the cavity. Food splatter builds up on it, carbonizes, and starts arcing. Here's the thing, you can clean it with a damp cloth if it's not too far gone, but once it's got actual burn marks or holes in it, just replace it. New covers are like $5-8 and they're easy to swap. Seriously don't keep running the microwave with a damaged waveguide cover because the arcing will eventually damage the magnetron, and that's when this goes from a cheap fix to a full replacement conversation.
Why does my RCA microwave blow a fuse when I open the door?
This is what happens when the door switches fall out of alignment. The monitor switch is designed to blow the fuse as a failsafe, basically it's saying something's wrong with the door safety system. So you'll need to replace the blown fuse AND fix the underlying switch problem, otherwise you'll just keep blowing fuses. Check whether the door latch is actually latching fully when you close it. Sometimes the plastic hook wears down and doesn't push the switch actuator far enough. Replacement door switch kits for most RCA models are under $15 and include all three switches.
Is it worth repairing an RCA microwave?
Honestly it depends what broke. Door switch? Absolutely yes, that's $8-15 in parts and maybe 30 minutes of your time. Ceramic fuse? Same thing, easy yes. But if the magnetron blew, sit down and do the math first. A replacement magnetron runs $60-80 for these units, and RCA microwaves retail for $60-100 new. So yeah, a bad magnetron on a budget microwave is usually a replace situation. Main control board is the same story. Anything in the high-voltage section, factor in the cost of a new unit before you order parts.
How do I reset my RCA microwave?
Unplug it from the wall and leave it unplugged for at least 60 seconds. That sounds too simple but it genuinely works for a lot of weirdness: stuck buttons, glitchy displays, error states after a power flicker. After you plug it back in you should see the colon blinking on the clock display, which means it's reset and waiting for you to set the time. If your keypad is completely locked and nothing responds, try pressing and holding the Stop/Cancel button for 3-5 seconds right after plugging it in. That clears child lock on most RCA models.
Why is the microwave making a loud humming noise?
That hum is almost always coming from the high-voltage section. The two main suspects are the diode and the magnetron. Here's how to tell them apart: a bad diode usually produces a hum that's pretty constant throughout the whole cook cycle and the food won't heat at all. A failing magnetron might hum more intermittently and sometimes still heats a little, just unevenly and slower than it used to. The diode's a $10 part and takes about 20 minutes to swap. Start there. If you replace the diode and the hum and no-heat problem both persist, then you're probably looking at a magnetron.

Models Known to Experience PROBLEMS Errors

This repair applies to most Rca microwaves with this error code. Common model numbers include:

RMW733, RMW953, RMW1138, RMW1414, RMW1205, RMW1645, RMW0701

MS

Written by

Mike Sullivan

Lead Appliance Repair Technician · 20 years experience

Last verified for technical accuracy on March 17, 2026