This problem isn't always as simple as simply replacing the blown fuse. First, you need to find out what type of fuse is causing the problem. There are two types of fuses: time-delay fuses and slow-blow fuses. You can find the type of fuse by looking at the schematic of the subwoofer.
The first problem could be caused by a defective coil. A faulty coil will have no electrical resistance, and a reading will not stay in place. To test the capacitor, you need a standard multimeter, which you can purchase from Amazon. You'll need to disconnect the audio input and power source before attempting to repair the subwoofer. To check the capacitor, insert the red probe into the positive lead and the black probe into the negative lead.
Another problem with a subwoofer is a
faulty power cord. A worn-out power cable can cause it to pulsate, or a blown fuse. If you're in a vehicle, try hooking it directly to the battery to check the voltage across the supply voltage terminals. If you've replaced the power cord, you can still use the subwoofer if it doesn't keep blowing fuses.
Other reasons for a blown fuse include overheating. If the power is too high, the voice coil can crash into the back plate of the magnet assembly or jam in the coil gap. This may cause the subwoofer to be underpowered and lack details. To prevent this, a replacement fuse should be installed as soon as you notice the problem. If the problem persists, you may need to re-solder the connection.