How to Fix a Blown Capacitor on Your Plasma TV for Under $5
What is a Capacitor and What Does it Do in a TV?
A capacitor is an electronic component that stores electric charge. In a plasma TV, capacitors help provide smooth, uninterrupted power to the sensitive electronics. When a capacitor blows or fails, it can no longer store a charge, causing the TV to malfunction or not turn on at all. Replacing a bad capacitor is often an easy and inexpensive fix to get your plasma TV working again.
Common Signs of a Blown Capacitor
Here are some common symptoms that may indicate you have a blown capacitor in your plasma TV:
- TV won't turn on at all
- TV turns off randomly or intermittently
- Distorted or discolored picture
- Unusual high-pitched humming or buzzing sound
- Cracks or leaks in a capacitor's casing
If your TV is exhibiting any of these issues, it's quite likely a capacitor needs to be replaced.
How to Test and Locate the Bad Capacitor
Before replacing any capacitors, you'll want to test them to confirm which one is faulty. Be extremely cautious when working inside your TV, as even unplugged, capacitors hold dangerous levels of electricity.
To safely discharge capacitors, use an insulated screwdriver to short the contacts or terminals on each capacitor before testing.
Here's how to test capacitors:
- Unplug the TV and discharge capacitors as described above.
- Remove the back cover of the TV to access the inside components.
- Visually inspect all capacitors on the power supply board for any obvious damage like bulging tops or leaking electrolyte. Damaged capacitors should be replaced.
- Use a multimeter set to measure capacitance to test each capacitor. Set the multimeter to microfarads (μF) and touch the meter probes to the capacitor's contacts. Healthy capacitors will show very close to their rated capacitance. Shorted or blown capacitors will show zero capacitance.
- Identify any faulty capacitors and note their location and capacitance rating printed on the side. You'll need this info when purchasing a replacement.
Buying New Replacement Capacitors
Replacement capacitors can be purchased very cheaply online or at electronics stores. To ensure you get the right components:
- Match the capacitance (μF rating) of the original part. Higher voltage ratings are OK.
- Match the physical size, especially the spacing between the contacts.
- Buy capacitors rated for 105°C for longest life.
- Opt for low ESR (equivalent series resistance) capacitors when possible.
For a single blown capacitor in a TV, you should be able to buy an exact replacement for $1-5. Buying a multipack can help replace multiple bad caps at once.
Step-by-Step Instructions for Replacing Capacitors
Once you have your replacement capacitor(s), here are the steps to safely replace them:
- Unplug the TV and discharge the old capacitors with a screwdriver as described earlier.
- Remove the back cover of the TV to access the capacitors.
- Desolder the leads of the bad capacitor from the circuit board. Apply solder wick or a solder sucker to remove solder.
- Clean the area with isopropyl alcohol and allow to dry fully.
- Insert the new capacitor in the correct orientation. Double check the polarity matches the old capacitor!
- Solder the new capacitor's leads to the board. Let cool completely.
- Use electrical tape to secure the replacement capacitor. This helps prevent stress on the joints.
- Reassemble the TV, plug back in, and power on to test. The TV should now work!
With proper safety precautions, replacing a blown capacitor is a straightforward repair anyone can tackle. Investing just a few dollars in a new cap can save you hundreds on a service call or pricey TV replacement.