TV repair peeps in here please

D.Roberts

D.Roberts

D.Roberts

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Hi all well I purchased a LG 32LC56 AEC LCD tv today it has a problem the lady showed me it working at her house when I got it home it wont turn on.

The lady did say it had this fault and it takes up to 10mins to work.

I have plugged it in and after about 10mins have a power led light come on it now flashes red then tries to come on so goes green but then goes off and shows red again and continues this.

When it tries to come on it creates a very small static noise form at the moment I am unable to get it on completely the lady did say its temperamental.

I think personally its a bad capacitor if so it should be an easy fix I just want to hear from a pro ;).

Thanks in advance.
 
Yup most probably a bad cap.

Had lots of these on stuff, Sky boxes, PC's etc.

Sometimes they are swollen, sometimes they have leaked, sometimes they have simply got a bad or dry solder joint.

Get a multimeter to hand to explore, and beware of the voltages lurking inside.
 
Hi thanks for the reply ok I will open her up when I get a chance I am a confident solderer etc but we will see hehehehe.

I will look around the mains input I am hoping its a Capacitor some where there.

Cheers
 
Ummmm I know what ya saying as its normally all done by robots now.

Maybe its more than likely a bad Capacitor and I can find and repair it that way I got me a cheap LCD tv hahahaha.

Apart from the problem above I have plugged me PC into it and it works great so far.

But I am worried to keep using it before I fix it in case I kill it completely would this be possible if it is just a bad cap? tho the lady said its been like it for a long time no and she has been using in..

Thanks
 
If the indicator light flashed with any discernible pattern it'll be worth checking up with the service manual to see what kind of fault is indicated. Often indicator lights on modern equiptment are linked to microprocessors to give rough indications of faults conditions through flashing patterns :)
 
PistolPete said:
Do you get dry joints in this day and age??
Click to expand...

I've known some components to get so hot they melt the solder down so it turns itself into a dry joint :p

It definitely sounds like a Capacitor problem (Like it's taking too long to charge) - however, I have no idea as I've never seen the back of the TV before :p
 
PistolPete said:
Do you get dry joints in this day and age??
Click to expand...

Yes thanks to lead-free solder.

All manufacturers skimp on component quality, too! At least the person doing the repair isn't worried about the unit price of a million capacitors and can therefore buy a replacement that will last longer than a day past the year's warranty.
 
Yes, capacitors (electrolytics specifically) and solder joints are still key failure mechanisms in electronics.

The issue with lead free solder is that it grows "tin whiskers", tiny hairs of tin protrude over time which can create short circuits between close spaced joints, which you see increasingly in modern electronics. The military don't use it, the old leaded variety doesn't grow these whiskers, something about the alloy keeps it more stable.
 
Dr.EM said:
Yes, capacitors (electrolytics specifically) and solder joints are still key failure mechanisms in electronics.

The issue with lead free solder is that it grows "tin whiskers", tiny hairs of tin protrude over time which can create short circuits between close spaced joints, which you see increasingly in modern electronics. The military don't use it, the old leaded variety doesn't grow these whiskers, something about the alloy keeps it more stable.
Click to expand...


Just had to google that.. :D

http://nepp.nasa.gov/npsl/Prohibited/tin_prohibition.htm

and

5qy5g.gif


http://www.aciusa.org/leadfree/leadfree_verdi-11-5-04.htm

I'm learndings! ;)
 
Last edited:
OK bugger this I am off to charge digi BRB.

I have circuit board out of TV now.
BTW I have TV flat on sponge nothing is touching screen itself will it be ok for a day?.
 
Last edited:
All righty then I have some better pics for ya.

http://img717.imageshack.us/i/sv201941.jpg/
http://img96.imageshack.us/i/sv201942.jpg/
http://img3.imageshack.us/i/sv201948.jpg/

There is a small amount of bulging on some of the Capacitors and some black stuff coming out of most of the ones with the very slight bulging.

So should I de solder the bad ones get more and do ya think this will fix it?.

Thanks for all your help

EDIT

The lady said its about two years old could this just be old age tho she did say it started after the power went out a while ago power spike?
 
All the bulging ones (all of them!?) need replacing, solder in new ones of the same spec (higher voltage units are also fine if they physically fit). Most of them have broken vents anyhow so they will have dried out quite badly.

I thought Samwha was a decent make, so perhaps the surge did take them out.
 
The power spike could have caused a power surge to the TV, damaging the caps.

I would definitely replace all those bulging capacitors. If you can, replace them all - but remember to take clear pictures from different angles, so you know which way each capacitor goes.
 
Great thanks like I say she said she had a power cut or something and since then it started to play up this was about 6 months ago I think.

She has been using it but she never turned it off as it would take 10mins for it to come on.

Ok watch this space I will de solder and remove old caps and get some more and let ya all know how it goes.

Thanks again
 
Ok update :)

I have removed the Capacitors and the specs are

10v
2200uf
105c (m)

35v
470uf
105c (m)

35v
1000uf
105c (m)

25v
1000uf
105c (m)

25v
470uf
105c (m)

Now I am totaly lost as to what ones to get from Craplins could any one help on this please :).

Pic of Capacitors : http://img411.imageshack.us/i/sv201962.jpg/ (note how much the plastic is pushed out at bottom)

I have the TV sat like this nothing is touching the screen and it will be like this for say 24hrs max as I hope to get it fixed tomorrow will it be ok like this?

http://img9.imageshack.us/i/sv201964.jpg/
http://img687.imageshack.us/i/sv201965.jpg/

Before : http://img688.imageshack.us/i/sv201955.jpg/

After : http://img96.imageshack.us/i/sv201957.jpg/
http://img121.imageshack.us/i/sv201959.jpg/
Thanks again all.
 
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