Dead TV after power cut LG 32LX2R

Strider590

lol you guy's make me larf! all this over a fuse rating?
If you must know, manufacturers have different ways of working this out. Most common is to use ohms law to work out the current consumption in amps and then double it, then fit the next highest fuse.
So if current was 1.6A they'd fit a 5A fuse.

Anyway, OP said it's not the fuse.

If the TV has been left on at the mains constantly, most LCD TV's are on standby if they're plugged in... lights or no lights.

The chances are the powersupply capacitors have dried out, simple to fix for anyone with a bit of electronics background and a good soldering iron.
Any 1000uf 16v electrolytic's would be top of my list for a change out, but faulty one's would appear to be bulging, possibly even leaking a brownish/yellow substance.

fox2319

hotkee wrote: »

And wattage is dependent upon what?

Watts (simplistically) = Volts x Current

The nominal power consumption they give on the box / manual etc. is steady state and does not allow for any power on in-rush, as a result the fuse rating is typically higher than that which would be suggested by steady state.

fox2319

Barneysmom wrote: »

The fuse doesn't deliver power, the TV draws the power, so for a test like this a 3 amp is fine. There will be one, maybe 2, glass fuses inside the casing of the telly, follow the mains lead through and you'll see the psu unit.
Not all fuses are instantly recognisable in electronics. Some look like little black slugs and are mounted on the pcb (soldered to)
Obviously take the plug out of the wall before you look.

It might be best to get a TV engineer in if you don't know what you're looking for. The reason I say this is because it might even have a blown rectifier.

All required current goes through the fuse. If, as is the case here, you suspect there may be something wrong with an internal fuse then tbh you're better off with a higher rating just to check things over on the outside of the tv. After that, you go inside...

Strider590

Forget the fuses, the fuse protects the TV and you in the event of a catastrophic failure.

Maybe the fuse is getting too cold? how about wrapping it in tinfoil to keep it warm? oh, you might want to stand WELL clear though, because your about to get a face full of the real problem!!!

NO, DO NOT DO THAT!!!

Honestly, they (fuses) don't just fail on their own without reason. They can also withstand short bursts of high current if they are time delayed fuses (which are used for any capacitive or inductive load). They are purely a protective/safety device.

sharkie

"time delay fuses" - sounds like 'Mission Impossible'!

Firstly check that there is power coming out of the socket - plug in the kettle in there and have a brew!

So you have checked the mains fuse, so the above post tell me. So now you have to decide on a new tv or repair the old one.

If you are repairing (or disposing of) you might as well open it it up as it is not working and have nothing to loose, so have a look around. I would particularly poke around the area of

• C221
• C222
• C213
• C214
• C210
• C211
• C207
• C208
• C218
• C219
• C202
• C203
• C204
• C205

It is probably best to 'poke' with the power cable unplugged. A magnifying glass may be of benefit and so may a torch. Personally, I would have thought a semiconductor or two would have gone as well as the caps.

Please remember that Capacitors can give you a good jolt and some you have to treat like batteries in respect too that they have a + and -

aliEnRIK

PROLIANT wrote: »

Just to add to the "Electrical Theory" debate, the reason the TV will have a slightly higher rated fuse is for the initial power on surge, when you power up a SMPS (Switched Mode Power Supply) of which every modern TV has these days, you get a surge of "current" for a few milli seconds as the power supply starts up, then depending on the overall "load" of the TV on the Power Supply, the TV will draw what it needs from the power supply it self, the there is a good reason that anti-surge fuses or time-delay fuses are not used in AC Mains equipment (standard consumer stuff anyway) and that is for safety.
So to overcome the initial power on surge a standard but slightly over rated fuse is installed.

A bit of Ohms law: P = V * I

P = Watts. (Power)
V = Volts. (Electro-motive Force)
I = Amperes (Current)

Good post pro. People forget about the initial 'startup' period.
The machines I power at work draw HUGH amounts of power before balancing out

fox2319

sharkie wrote: »

"time delay fuses" - sounds like 'Mission Impossible'!

Not really, you just get a regular fuse and put a bit of a coil at the end then let it's inductive properties react to the in-rush surge. Essentially, they survive a surge but not a sustained current

Raksha

Thanks for all the help people. OH has found a local firm who will have a look for £20, and have seen a similar problem before.

fox2319

Raksha wrote: »

Thanks for all the help people. OH has found a local firm who will have a look for £20, and have seen a similar problem before.

Glad to hear it, hope all goes well.

JimBoB_5

Thanks to this thread (and some others on the interweb) I have fixed my 32lx2r tv! Same symptoms, no power after I had some electrical work done and the power was shut off. I bought 14 replacement capacitors for the Yuyang branded power board, soldered them on and *BAM* a working tv again. The old capacitors were Samxon brand, some sites like them others don't. None were "bulging" as traditional bad caps do and looked perfectly fine, but the power board itself really does look like the cheapest part of the TV.