Sharp R930AW oven doesn't work

IF, you experience a problem similar to the one in which one or more of these switches can cause, always suspect first an item or component that is mechanical. In other words, the parts that have moving parts usually provide symptoms that appear to be very complex in nature, but are simple in what it may take to remedy or fix. For instance, if the convection portion of an oven as the R-930AK does not work or is intermittent, look to these referenced switches. I've even had the unit work when tilted at some degree of angle and stop working when moved beyond that angle. This was caused by an old switch. Actually, the fatigue and dirt with age, had caused the little pink actuator to only work when at an angle beyond that of horizontal which then did not require as much tension to allow to go shut. It was almost like a mercury switch on a thermostat or a pendulum anti-tilt switch on a pinball machine. Remember, what can wear out, probably will.

I would first suspect a bad door switch. I've pasted in the text of my file on diagnosing and replacing door switches below. Otherwise, you may have a loose conneciton on a wire that connects to the magnetron terminal. That would have to be pulled off, tightened with pliers and then reinstalled. But before you or a friend does any work inside of the oven, I would strongly recommend you read my safety text, which is attached below. # # # MICROWAVE OVEN CRITICAL SAFETY WARNINGS copyright 2004+ updated Nov. 19, 2006 William E. Miller, AS-EET http://www.MicrowaveDisplay.com NOTE: If you decide to disassemble or otherwise attempt to repair a microwave oven or other appliance, you do so of your own free will, and the author of this document assumes no liability for the consequences of your actions. If you disagree with this concept, we would advise you not to attempt any such endeavor. We offer these safety warnings, some of which may appear repeatedly in this document for clarity. MICROWAVE OVENS UTILIZE AND PRODUCE DEADLY VOLTAGES WHICH CAN BE INSTANTLY LETHAL! These hazards can be eliminated simply by following these two basic rules: 1. Always be totally sure the microwave oven is unplugged from the wall (disconnected from power line) before attempting any disassembly. 2. Always discharge the high voltage capacitor before touching any components or wiring inside the unplugged microwave. (details below) POWER LINE VOLTAGE Power line voltage can be instantly lethal. Always be completely sure the microwave oven is totally unplugged from the wall (disconnected from power line) before attempting any disassembly. If you are ever in the presence of a microwave oven (or other appliance) which has its cover removed but is still connected to the power line: - do not touch any component inside the appliance (even with an insulated tool) - wear non-conductive or rubber-soled shoes - be sure you, your shoes and clothing, and the immediate area are all dry HIGH VOLTAGE AT HIGH FREQUENCY Microwave ovens produce and store high voltages which vary from about 3,000 to 5,000 volts. These voltages can cause heart failure, heart defibrillation, and/or extensive injury, any of which can be instantly or eventually fatal. If you are ever working in the presence of a microwave oven (or other appliance) which has its cover removed but is still connected to the power line: - do not touch any component inside the appliance - wear non-conductive or rubber-soled shoes "Live" testing while the oven is running is NOT recommended for anyone who does not have proper training and experience. Always discharge the high voltage capacitor before touching any components or wiring inside the unplugged microwave. (details below) MICROWAVE RADIATION Microwave ovens produce microwave radiation. While it is not the ionizing type of radiation that is known to cause cellular mutation, microwave energy can cause serious burns and injury. Never attempt to bypass "jumper across" or otherwise defeat any safety device such as door switches in a microwave oven. The switches are basically designed to prevent the oven from running when the door is open. Never attempt to power or operate a microwave that has a damaged, misaligned, or removed door or door panel or part. SHARP EDGES Microwave ovens are made of sheet metal and other parts that have very sharp edges and corners that can cause very serious cuts. Such cuts and slashes often occur when a person experiences a shock, etc. from the microwave oven, then reflexively pulls back his hand or arm. It is recommended that you remove any watches or jewelry when working on or near appliances, since they can get caught inside, posing a serious safety hazard. HEAVY MAGNET WARNING Microwave ovens contain a device called a magnetron, which contains a very large and powerful magnet. This large magnet can disrupt or seriously damage watches and pacemakers. STATIC ELECTRICITY The components on the printed circuit board are static-sensitive devices and can be damaged by static electricity, even if you do not feel a discharge. While this is not always an issue on a board assembly, it is still best not to touch these components or the control panel without properly discharging yourself first. This can be done by touching or maintaining contact with the metal chassis or screw of a properly grounded appliance. But NEVER do this if the appliance that is apart is still connected to the power line. DISCHARGING HIGH VOLTAGE CAPACITORS A microwave oven's high-voltage capacitor is used to produce final high-voltage. While it does have a "bleeder resistor" designed to drain the high voltage charge after cooking stops, anything can fail, so it's safer to discharge the high-voltage capacitor to prevent an electric shock. Always be totally sure the microwave oven is unplugged from the wall (disconnected from power line) before attempting any disassembly. It's a good idea to wait a few minutes after unplugging the oven before discharging the capacitor. When you discharge the capacitor, a loud pop may result. It is not harmful. Just be aware that it may happen, so you are prepared for it and a reflex reaction does not cause you to be injured. You must use an insulated tool such as a screwdriver. Be sure the handle is plastic or has a rubber sleeve. Never use a wooden handled screwdriver, as the wood can absorb moisture and conduct, giving you a shock. Be sure your hand and the tool are clean and dry. If you have a dry rubber glove with no tears or holes, that would help prevent contact with the stored charge, too. Refer to this photo to identify the capacitor: http://207.234.249.73/mwd/discharge.jpg Discharge procedure: 1. Touch the blade of the screwdriver to one of the terminals of the high-voltage capacitor, then slide it against the other terminal and hold it for a second or two. If you're going to hear a pop, it's when the two terminals get shorted. 2. Touch the blade of the screwdriver to one of the terminals of the high-voltage capacitor, then slide it against the metal of either the case of the capacitor or the back panel of the microwave. 3. Touch the blade of the screwdriver to the other terminal of the high-voltage capacitor, then slide it against the metal of either the case of the capacitor or the back panel of the microwave. Some microwaves made before the 1980s may have a capacitor built in to the magnetron, but we do not recommend servicing these at all. # # # MICROWAVE OVEN DOOR SWITCH TESTING & REPLACEMENT copyright 2004+ updated Nov. 19, 2006 William E. Miller, AS-EET http://www.MicrowaveDisplay.com By utilizing information on this site, you agree to hold the owner harmless and blameless for any consequences arising from your decision to take apart or inspect your microwave oven. See the following safety warnings before you proceed. What usually causes these switches to fail is opening the door while the oven is cooking, instead of using the "stop" pad on the control panel. Every time the door is opened during cooking, the switches get hit by an electrical arc that will cause them to fail in time. My customers are always surprised to hear this, but it's something that most people do without thinking. IMPORTANT: Please, please be completely sure the oven is unplugged. Also, the microwave produces voltages over 3000V and can be instantly deadly, causing cardiac defibrillation. It is one of the most dangerous appliances if not handled properly. Also, once you have the cover off, you need to be able to identify the high voltage capacitor so you can discharge it before you begin work. For details on this and other VERY important safety precautions, see: http://www.microwavedisplay.com/safety.txt Next you'll need to find the switches. With the cover off, look around from the right side and they're located where the hooks on the door go into the chassis of the oven. Here is a good diagram which represents a typical microwave, showing where they are: http://www.gallawa.com/microtech/how_work.html Here is a good explanation of how the switches work and a closeup of the terminals on the door switches: http://www.gallawa.com/microtech/switch.html Often the switch will be held in place by a plastic retaining hook which may be beneath the switch and hard to see. A marked diagram is at: http://207.234.249.73/mwd/doorsw_release.jpg There is an upper switch and a lower switch. There is also a switch in the middle, the "monitor" interlock. It is wired differently than the door switches. In addition, there may also be a separate door sensing switch. As you open & close the door, watch how the switches activate. On the bad one, you'll probably see that its black or red activator button (which is pushed by the door hook) is not moving out when the hook moves away from it. Even if only one switch is bad, technicians will usually replace all three switches to ensure that the safety function is preserved and the customer is protected. The current that flows through the top interlock also flows through the bottom one, so if one is stressed, the other will probably fail before too long anyway. The peace of mind is worth it. If you do end up replacing the switches, be very careful to replace them one at a time (like spark plug wires) and be sure each wire goes on the same terminal of the new switch the same way it is on the old one. This is especially true for the center monitor interlock switch. I strongly recommend that you do not remove the plastic piece(s) that the switches are mounted to. The plastic pieces are precisely aligned & mounted so that the door is held shut properly and will not emit microwave leakage while cooking. It's definitely best to remove the switch itself from its mount. You should be able to get switches from local appliance parts stores. You can se a representative photo of such a switch here: http://207.234.249.73/mwd/doorswitch.jpg If this does not help you, please e-mail me at [email protected] For microwave control panel repair, see http://www.MicrowaveDisplay.com