The amount of work depends directly on the type of microwave panel. In many brands, Daewoo or LG touch screen has to be changed in one unit with the entire panel. Therefore, the microwave is more often sent to the workshop. But even if you manage to remove the unit with the screen, it is impossible to work with it without a special tester, and if you disassemble it carelessly, you can easily break the cable.
Therefore, you can try to repair it at home only in the case of microwave ovens with a membrane panel. Another thing – microwave ovens brand Samsung. It is easier to work with them since they mostly have sensors on membranes.
Step one – disassemble the oven
The first thing we do is to de-energize the device and remove the outer casing. Almost all microwave ovens are disassembled in the same or similar way. Unscrew the screws on the back with a screwdriver and remove from the body cladding – the lid and the side walls, all this is one element in the shape of the letter “U”. All that’s left is the front with the door and the back wall.
Find the panel. The part itself is plastic, attached to the frame of the microwave with a couple of self-tapping screws. You will need to work with a screwdriver to unscrew the fasteners and remove the wires. Carefully disconnect the cable from the display, with which the panel is connected to the unit. After that, you can remove the keyboard from one unit along with the plastic box and the board.
The keyboard itself is a flexible plastic strip glued to the front of the box. The control part is made in the form of a board. There may also be damage to it, preventing the microwave from working steadily under load.
Step two – diagnosis
The most difficult thing is to determine the cause (there can be several), for which the panel does not work. The first thing to do is to do a visual inspection. Sometimes the reason why the panel does not work lies on the surface.
Immediately pay attention to the delamination of conductive tracks, broken contacts, and oxidized surfaces. Perhaps some parts on the control board look burned out. If the unit was constantly overheating due to excessive voltage, the first to be damaged (blown) capacitors.
The first thing to do is:
Inspect the stub and metalized sublayer, especially under the start or stop buttons. The microwave may not work if there are broken tracks or conductors, or if there are dirt or grease deposits on the contact surface.
Inspect the circuit board, and check for a break in the fuse. Usually, the microwave doesn’t work because the fuse is burned out.
Inspect the parts on the board. If there are blown capacitors, this is definitely one of the reasons why the panel will not work.
Check the fixing of the cable in the connector on the board. Often water and grease vapors from heating the microwave get inside the connector, which can cause some of the panel’s buttons to not work.
Common damage is the breakage of the current-carrying track on the cable. The damaged place can be seen with your eyes, even without the need for multimeter testing. But you need to be careful, the loop can be damaged while disassembling the microwave and removing the panel. Therefore, the oven may not work for another reason.
Step three – how to repair
Repair work must start with the circuit board. Before attempting to repair it, you need to clean all the contacts on the circuit board with alcohol.
The next step is to check the stub itself. If there is a breakage, it must be sealed with conductive glue, over which to put tape.
There are a couple of relays on the microwave control board. If it visually works but there is no heat, the switching relay is most likely the cause. If the oven is working every day, the life of these parts lasts a maximum of 5-6 years.
If possible, you should replace the relays, even if they are in working order. The microwave will be able to work for at least another 5 years.
The last operation is to clean the tracks on the membrane keypad itself. Initially, we wipe and clean the surface with a tampon moistened with alcohol. If you can see gray spots on the contacts, you can additionally erase them with a rubber drawing eraser.
You can glue the membrane keyboard with a few drops of glue and immediately install it on the microwave, you need to check how the oven works after repairing the panel.
Whether you can find the breakage yourself or at some stage of the search call a master – it is up to you to decide. Just note that if you have no experience in disassembling and reassembling a microwave oven, it is better to limit your external examination and search for simple damages, and then call our handyman. Chula Vista Appliance Repair Company is happy to offer efficient microwave oven repair services in and around San Diego County. Our team of experts is well-equipped and ready to handle all types of microwave oven repairs, regardless of their complexity. We strive to provide excellent repairs using only high-quality replacement parts backed by the manufacturer’s warranty, so you can rely on a microwave oven repair specialist to fix the problem and keep your machine working properly for a long time.