Hey everyone, I'm new here and am trying to save a 32" lcd tv. I was reading another thread on here about fixing a tv so I figured I'd give it a shot. I currently have it on the chopping block. The tv will not power on manually or with the remote, there's no clicking noise, no LED light on the front, no signs of life. There is no obvious damage to the unit, no rattling around, nothing out of place. I am thinking it is either the power plug itself, or the power board. None of the capacitors look suspicious, no funny colors or bulging, and I'm stumped. This tv is less than 2 years old. Any thoughts would be appreciated so I don't have to keep using my tube tv.. grrr!
Power supply. Almost always is.
If it isn't - it's usually the switch.
If it isn't that, it's probably toast.
Any smells from it? If there are - it is probably toast. Burning PCB (basically fibreglass) is unmistakable. The smell of burning polyester resin (the bonding agent) is rather distinctive. Burning epoxy (what most chips are potted with) is also distinctive. Both are unpleasant smells.
Anything black, burned or smoking? If so it is toast unless it is a simple sub assembly to replace. This has worked for me for years with computer repairs. Does the PSU work? Replacing it will usually fix a wide range of problems.
If not - look (and smell) for the smelly bits. Anything black burned or smoking requires replacing. If you can't find anything and there are no bulged capacitors then you have a software problem which is not my problem.
Check voltages - especially if you can find a manual for it and what the voltages ought to be.
I agree with Don. Check the power supply and the switch first. If they're OK then its probably toast. If you find any in there that'll be it. Get it out immediately and be careful where you leave your breakfast in future.
Don,
There's no smells coming from it, and nothing is blackened or charred, it's just like a car that won't turn over when you turn the key. I did try another power cord, and that wasn't the issue, so that's what made me think it was the power supply. If this is the case after testing, I can just swap it out, right? I will have to help my dad help me with the voltages, I am not at home at the moment and have no way to test. This is just frustrating.
At that point I'd try plugging it in elsewhere - power sockets have been known to go bad.
Check the internal fuses - they usually die for a reason - but sometimes just die. These are usually removable.
Are there any signs of life at all when powered up? This will give hints as to what has failed. If it looks like it ought to switch on (i.e., it goes into standby) I'd look at the switching part as the most likely culprit. Sometimes jumpering out the switch circuitry (basically soldering a wire over it) will do the trick if the switch has failed (better to replace it though) - you do have to unplug it (Since you say you are from Pittsburg where I spent two very enjoyable weeks in August I'm assuming your power sockets aren't switched as they don't seem to be in the US) when you aren't using it.
As far as the fuses go, just the one glass one? I am going to start with the most obvious repairs before getting too crazy with it!
Check that fuse. Usually you can see if they have blown. But sometimes you can't. Pull the fuse and replace it with one of the same rating. A very basic multimeter (Like under $10 from Harbor Freight - your nearest one would appear to be in Robinson Township - 5185 Campbells Run Road) will test for continuity. If there isn't any - the fuse is dead. Replace the fuse and all may be well.
Alternatively: Temporarily (very temporarily) replace the fuse with a paperclip. If the paperclip melts or a fire happens then the TV is toast.
ok so here's my question...the fuse has two little lumps on the wire inside of it, does that mean it's blown? i thought it was either a coil or a straight filament...
That was me that had that problem. check the power supply board for bad capacitors. usually they balloon out on top or just pop. desolder the bad ones and go to radio shack for similar rated ones.
If you can see a solid wire/connection from one end of the wire to the other the fuse is OK most of the time.
Sounds blown to me. I'd be almost certain from that description that it's dead.
Sometimes they just blow - sometimes it is for a reason. Replace it with an identical one (It is very important that it is the same voltage and current value - and length obviously). If that blows immediately, it almost certainly blew for a reason. I'd try another fuse them - if it dies immediately the simple diagnosis is that it is going to cost a lot to fix.
That reason might be hard to trace without the appropriate test gear. Which costs a lot.
If it doesn't die immediately I'd think about getting a surge protector - preferably a ferroresonant line conditioner but they weigh about the same as a truck though they can be found cheaply enough on eBay. Most cheap MOV surge protectors are essentially useless.
Ok well the fuse has some lumps so im not sure, ill run down to radio shack and check out the situation, might as well start somewhere! P.S. if I seem at all ignorant, I was a psych major, not an EE, which I am presently regretting..
I was going to link to the other thread about the capacitors, but i didn't know how yet, this is my first hour here lol! Maybe they're on the verge of going bad and I just don't know it...
Try to find information for your TV Model # and you can buy any part on Ebay. I fixed one a long time ago. All you have to do is resolder the legs of the plug where the power cable attaches to the back of the motherboard. Some how the soldering gets cracked. It might be from the heat given off by the tv. I repaired the motherboard of my windshield wipers the same way.
Ok so I replaced the fuse, and then I plugged it in and got shocked a little bit, so at least I know it's not the female end of the plug. I'm not exactly sure where the power goes in on the backside of the motherboard, everything seems to plug in on one side...
Sounds like a slow blow fuse, it will take the higher inrush current when the TV is first switched on when capacitors are charging the amount of current will then settle back to normal levels.
Similar to
This thread has actually save me $$$ from buying a new plasma TV this weekend. after reading this thread, I try to repair my LCD tv that click for hours and won’t power up.it never occur that I am able to repair a TV til this thread trigger the idea. So I search the Internet, change the capacitors, less than 5usd.less than 2 hours labour and now my tv can power up in few seconds with no click sound.with the $$$ saved, I can buy a few more flashlights.
A free advice. When you shop for capacitors absolutely get the ones tagged with low ESR or you might find yourself re-changing them often.
A decent simple read:
Advise noted. I know what to lookout for if the capacitors fail again. Thanks
brand,model,pictures of the inside,ect.
is the standby voltage there?
without more info its just wild assed guesses.