Introduction: How to Fix a TV That Won't Turn On
Modern flat screen TV's have a known problem with capacitors going bad. If your LCD or LED TV won't turn on, or makes repeated clicking sounds, there is a very good chance that you can save hundreds of dollars doing this simple repair yourself.
I know, I know. You're thinking, "Tinker inside my LCD HDTV. Are you crazy?" No, I'm not crazy. This is a repair almost anyone can do and this fix will work for any TV.
You sit down and get comfortable, ready to watch your favorite TV show or movie. You turn on your TV and...nothing! Unsure if you hit the power button, you try again...again, nothing! But you do notice a clicking sound emanating from your TV.
"What the heck? No...Oh, crap!"
HDTV's aren't cheap. Most of us have to save, or at least be prepared to spend $800-$1000 on new one. Heck, I'm sure many of you don't savor the idea of spending a few hundred on repairs.
I have good news. This repair is actually quite simple, and with only a few basic tools and about 20 bucks, you can have your TV working in less than an hour.
The step-by-step repair below was done on my Samsung LN46A550 46" LCD HDTV, but this is an easy repair on any TV.
The bad News. If your TV is physically damaged in any way, been dropped, has a broken screen or gotten wet then this repair isn't for you. But if your TV was working one day but not the next, read on.
Step 2: Tools Needed
You will need 5 basic items below for this repair:
- Soldering Iron & solder
- Phillips Screwdriver
- Wire Cutters
- Replacement Capacitors from Amazon
If you need a soldering iron, that no problem. They are cheap and easy to use. I highly recommend this 60 Watts Soldering Iron Kit. It's less than 20 bucks. If your looking for the lowest price possible, this 60W soldering iron with stand is about $8 (shipped prime) and will work fine.
Step 3: Optional Tools
These tools aren't required, but they can make the process easier.
- Magnetic, ratcheting, flexible screwdriver (to help remove all the casing screws)
- Cordless Screwdriver (to help remove all the casing screws)
- Desoldering wick (absorbs melted solder)
- Solder sucker (remove melted solder)
- Flux Pen (flux on solder makes it flow and less "sticky")
- Multi-Meter (test for bad Caps, helpful if there are no visual clues)
Step 4: Remove Stand and Wall Mount
After unplugging everything on the TV, you will need to remove the stand. If your TV was wall mounted you will need to remove the TV from the wall, and remove the mounting bracket from the back of the TV.
Red arrows: Remove these screws to remove stand from TV.
Blue arrows: Remove these 4 screws to remove a wall mount (not shown) from your TV.
The TV sits on top and inside the stand, so it wont just flop over when you remove the stand screws, but it's always safer to have a friend hold the TV upright as you remove the screws from the stand. Then each of you grab a side and carefully lay it flat on a carpeted surface.
Step 5: Warning
When handling your TV always keep it straight up (like your watching it)
or laid flat. Any force applied at odd angles can damage the fragile glass front.
Step 6: Remove All Screws That Attached the Back Casing of the TV
Above is a a picture of the back side of a typical TV. The left picture is my LG 42LN5300 and the right picture is my Samsung LN46A550, but all TVs are similar. Remove all of the screws along the outer edge of the back casing. There can be anywhere from 10 - 16 of these screws.
There will also be screws within any area where the are power or cord plugins. You can see these in the lower middle of the pictures. (highlighted with the red rectangle on my Samsung)
Step 7: Don't Forget the Hard to Find Screws
Often in the area where you plug in cords a screw or two can be found. remove these as well.
Step 8: TV With Back Casing Removed
With the back casing of your TV removed take a picture of your TV. This will help during reassembly.
Then identify the "power board". Every TV is a little different, but the power board will have can shaped capacitors and is the board that the main power from the plug goes to first. On this Samsung TV I put a green rectangle around the power board that we will be working on..
The other "green" board is the "logic board", this is the computer that runs the TV. Repair of the board is beyond the scope of this article. (But it's most likely not the problem)
Step 9: Remove Wiring Harnesses From Circuit Board
Remove all of the wiring harnesses from the circuit board. A simple tug on the connector clip (not the wiring) should be sufficient to remove them. On this particular Samsung board there are 7 different harnesses.
Step 10: Remove Screws Holding Down Circuit Board
Remove the screws holding the power board to the TV chassis. Most boards will have 6 screws holding them down, as does the one shown in the picture. But look it over there could be more or less.
This is a power supply board and not particularly sensitive, but it is always a good habit to handle these boards carefully and by the edges.
Step 11: Identifying Bad Capacitors
This TV repair focuses on the small "can shaped" Aluminum ElectrolyticCapacitors. These capacitors come in many colors and sizes but are easy to find on any power board. Not only are these the most likely cause of your problem, but bad ones are simple to find and simple to replace. In most instances you will be able to visually identify the bad capacitors. You don't need any special skills in electronics or testing.
Step 12: Visible Failure #1 - Bulging Vents
When a Capacitor fails, the chemical reaction inside the capacitor can produce hydrogen gas, so capacitors have vents cut into the tops of their aluminum cans. These are intended to break and release the gas that has built up inside the capacitor. So, a capacitor which has failed can show bulging at the top..
Step 13: Visible Failure #2 - Leaking
Another sign of a failed capacitor is leaking fluid (electrolyte). This can be an orange or brownish discharge from either the top or bottom of the capacitor. Usually, with leaking the capacitor will also be bulging. But a capacitor can bulge but not leak.
Capacitors do not always show visible signs of failure. But, if you see either of the 2 signs above on your board, you can be confident that you're close to fixing your TV. If you don't see these signs of failure, but your TV had the tell-tail clicking sound, you still can be fairly certain the steps below will fix your TV.
Step 14: Find the Bad Capacitors on Your Board
On power board pictured above, I have indicated which capacitors you should be examining for signs of failure. These Capacitors are Aluminum Electrolytic Capacitors, and are the most likely cause of your problem. The capacitors with the green arrows are the most likely candidates for being bad, but the blue arrow are other capacitors to examine.
Don't worry if your board looks a little different. Simply examine all of the capacitors and usually the faulty one(s) stand out.
Warning: Do not bother with the large capacitors (2 or 3 will be on every board). These are high voltage, rarely fail and for safety require a little more expertise to work on.
Your board probably looks different, that's OK, just examine any and all capacitors on your board that look similar to ones pointed out above.
The pictures above are actual closeups of my TV's board. Notice how the blue capacitors in the foreground are bulging. These are the capacitors I will replace. All other capacitors look OK. If you can find replacements for all 4 of these capacitors, and any others that show visual signs of going bad, I recommend replacing them all while your in here.
Step 15: Removing the Capacitors
Capacitors have polarity. What this means is, like a battery, they have a positive (+) and a negative (-) side. Before removing any capacitor, note which side the white stripe of the capacitor is facing. You will need to put in the new capacitor in the same direction. You probably noted on my pictures that I actually made a note on the aluminum heat sink with a pen.
Step 16: Let the Iron Do the Work. If the Capacitor Does Not Easily Pull Out, Do Not Force It.
Now that you've identified the capacitors that look bad, turn the board over and carefully identify exactly which points on the board are the wire leads from the these capacitors.
Circle them with a "sharpie" type pen to keep track. Grab your friend and have them help you on this next step. Balancing the circuit board on its side while using a hot soldering iron and pliers can be a bit tricky.
Plug in the soldering iron and give it 10 minutes to get hot.
With the circuit board on its edge, have your friend grab one of the capacitors with the pliers and apply a very gentle pulling pressure. Apply the tip of the soldering iron to one lead on the back side of the board and hold it there until you see the solder melt. Now switch to the other lead until it melts. Keep going back and forth on the leads. Each time the solder will melt faster. After going back and forth a couple times the capacitor will easily come out.
Repeat for each capacitor that you are replacing
Step 17: Time to Go Shopping
Capacitors are rated for their application and you must replace like for like. There are 3 ratings to identify:
- uF (micro farads)
uF (micro farads)
Ideally you should match the uF and the temperature rating exactly. But it is acceptable to use a capacitor rated higher uF if it is within 20% of the original.
Try to match the temperature rating, you can go higher, but not lower.
Match if Possible. You can use a larger value if needed. Not Lower.
Often you can find replacements capacitors at your local electronic store. But it may be easier to buy replacements from Amazon.com.
For my repair I needed;
1000uf 10v Capacitor 105c High Temp, Radial Leads
820uf 25v Capacitor 105c High Temp, Radial Leads.
Step 18: Install New Capacitor
Insert capacitor, making sure to place the negative side in the correct location.
(Look at your notes and pictures to make sure you are correct)
If there is hard solder in the hole, simply apply the soldering iron until solder melts and slip capacitor leads in.
Step 19: Bend Back the Leads to Hold the Capacitor in Place.
Step 20: Carefully Clip the Leads So That Only About 1/8" Is Protruding.
Step 21: Solder Leads
Place your soldering iron and solder on lead until the heat melts the solder. Once solder melts onto the lead, apply the iron on the lead and solder a few times to melt the solder cleanly on the lead. If you have solder flux, the solder will make a clean connection.
Step 22: Finished
Capacitors installed! If there is any flux or solder residue, simply clean the area with a damp cloth.
Step 23: Reverse the Process
- Attached the circuit board with the six screws.
- Reattach all seven wiring harnesses.
- Replace the back cover.
- Turn on TV and be happy that you save yourself a ton of money.
This fix works and it worked for me.