Fixing a Voltage Stabilizer(plus Repairing Tips).

Voltage stabilizers are used to prevent voltage fluctuations from mains that could harm some devices like refrigerators, Televisions, air coolers, etc. But from the video above you can see even if the input voltage from mains seemed stable, the output of the stabilizers seems to be fluctuating a lot. You cant hear it in the video but I could hear the relay switching on and off. This can really damage your costly appliances. So here is a guide to repairing it. From the video, you could see that the insulation of the wire coming from mains to the inverter is torn or bare, even though the copper is not bare with more stress it could cause it to expose the copper, so we are also going to be fixing that. It also looks a bit dusty so we also will give it a little clean.

WARNING!!!

Don't do this if you are not sure what you are doing. Dealing with mains circuitry can be dangerous.

no. 1 tool for repairing electrical appliances is a multimeter, make sure you use a well-rated one

You would also need few common tools like screwdrivers, pliers, and other basic tools for dismantling the appliance and fix it

You would need a Soldering Iron/Station and tools with it(like Desoldering wick/pump, solder, flux, etc) to fix any solder joints, replace some components, etc.

You also will need a cleaning brush or old toothbrush, a cleaning cloth, and some cleaning agent or IPA.

To fix the wire we will be using two compounds epoxy and electric tape.

Make sure the stabilizer is unplugged and start removing the screws holding the case. Make sure you don't lose the screws so keep it in a small container for now. After removing the screws open the outside case and take a picture of the things inside so you don't have to suffer trying to fix it back. With the picture, you can get an idea of where the parts are supposed to be.

Now we can remove the screws holding the circuit board and the plastic case next to it to get a closer look at the board. Now taking a closer look you can find the bulging capacitor on the top left side. This is the main culprit that is causing this problem and also one of the most common problem in most apliances. We just have to replace it with another capacitor. We can also find the schematic of the circuit of the certain appliance by typing its brand and model number, to get an in-depth look.

After identifying the faulted capacitor, to remove it we can add some more solder to its joints and simultaneously heat both pads using a soldering iron while trying to pull the cap from the other side. Using this method you can easily remove the capacitor.

After removing the capacitor it is time to replace it with another capacitor of the same capacitance and the voltage rating should be the same or higher. It should not be replaced capacitor of voltage rating lower than the original capacitor. And some of the reasons why capacitors swell are, overvoltage, overcurrent, or overheat. It is always a good idea to replace the capacitor with the same dimensions. In this case, the original capacitor is a 1000uf 25v capacitor, but I had only two types of capacitors with the capacitance of 1000uf, one was rated with 63v and it had a larger dimension than the original one and the other one was the same dimension as the original one but was rated 16v and due to the lockdown where I live I couldn't get the capacitor with the exact values as the original one so I had to use the larger one, which is not really a good option, but I will change it when I get the capacitor with the exact same values. When replacing the capacitor first remove the solder from the pad where you have to solder the cap and when placing the cap make sure you don't mismatch the polarity, it could cause some magic smoke to come. The negative side of the cap is usually marked on it, and the shaded white lines on the board is where the negative lead of the cap should go. First place the cap, bend the leads on the other side, solder it and then shorten the leads.

Now it is time to clean the whole stabilizer. To do this we have to remove the transformer. For which we have to carefully remove the screws while holding the transformer and gently placing it down. First, we can remove the dust by dusting it with a toothbrush and a paintbrush. Then we can use a cleaning agent or some IPA with a cloth to clean it. You can see the multipurpose cleaning liquid I am using above and it was able to remove some black marks inside the case.

Now it is time to fix everything back together. First, we can fix the transformer and when fixing the transformer never forget the ground wire that connects to its metal part, I REPEAT, NEVER FORGET IT!!!. Also, replug any plugs you removed when opening it. Now we can assemble the other parts and finally cover it with the case and screw the screws using a screwdriver. Now we are almost done but still, we have to fix the wire coming from mains.

The insulation usually gets removed due to strain, so we are going to be using some two compound epoxy to hold the three wires together tightly and wrap some electric tape tightly around it to help it from bending.

It works now!!! at the output, I get close to 217VAC, which is fine and it also seems to work well for my refrigerator.

1.Don't use the brush, you used to dust, to brush your teeth.

2.When removing the case store the screws in a small container and store different types of screws separately, to help when fixing it back.

3.If you see any large capacitor, please discharge it using a resistor or short it through a screwdriver before working on it.

4.When soldering either do it on a well-ventilated space or use something like a fume extractor or fan to get rid of the fumes.

5.Never work on an appliance when it is plugged in.

6.Use schematics of the appliances you are working on to get a better look and find the culprit.

7.Take a small break every 30 mins you work, you don't want to strain your eyes too much and it also increases your productivity.

I HOPE YOU HAVE A GOOD DAY
THANK YOU!!!