Can't identify the problem with my lcd tv

Jolo · 06-11-2008, 11:25 AM

Hi Guys!

Im planing on buying a cheap, really cheap, lcd tv. The reason for this being so prizey is that the person selling it can't identify the reason to the tv malfunctioning. nevertheless, ive tried searching the web but with no sucess, so thus im contacting you guys. i know you're far better than me at finding the right information. So the problem is as follows:

When the owner of the tv starts it, the diode that's supposed to be green shifts from green to red, back o green, to red etc. - flickers between the two. There is neither picture nor sound.

The brand and model of the tv is: Stevison 2661 (32 inch)

im from sweden and there's no such tvs here so maybe its imported from the states or england.

i would apreciate any kind of information about the tv or, at best, an answer to what is wrong with it.

best regards
jolo

**Done_Fishin** · 06-11-2008, 03:08 PM

The TV is probably (but not limited to) having problems with the power supply.

the possibilities are that

1 .. the power supply is having problems starting up due to a fault within the supply

2 .. the power supply is having problems starting up due to excessive load causing it to trip out.

I do not know the particular brand or model, but experience dictates that the best place to start search is by thoroughly examining all areas of all boards for swollen or leaking capacitors. Anything that looks like it might be anything other than a perfect flat topped capacitor is suspect and should be replaced with a capacitor of the same type, voltage , capacity and temperature rating. I prefer to change all capacitors that are 85 degrees celsius for 105 degrees celsius.

If a capacitor needs changing but you can't find something of the same value and voltage rating .. ALWAYS take the next value larger .. so if you have a capacitor that is rated 6.3Volts .. but can't find one .. use 10 Volts or more NEVER use one that is rated less than the original .. it will fry very quickly ad probably cause a few more problems as well!
If you need a 270uF capacitor then a replacement would be 330 uF or even 470uF. Take care not to go too high .. that can cause other problems too .

Preferably, if you don't know about Electronics,

DONT OPEN THE TV AT ALL!!.

There are lethal voltages inside that can kill even if the set is switched off!

Jolo · 06-12-2008, 03:40 AM

hi again, and thanks for the quick reply.

the thing is that i dont know anything about hardware in a tv, sov thus i guess that my only option is to leave it to professionals. however, two questions comes to mind , 1) how likely is it that the problem has to do with the power supply? very likely, like 90%? 2) How difficult is such a procedure for an expert, i mean - will it cost me a fortune to have them fix it for me or is it quite easy to fix, and thus quite cheap?

cheers
Jonatan

**Done_Fishin** · 06-12-2008, 11:26 AM

Since I have no idea at all of what is inside this particular model .. I just couldn't say ..

Point is that the power supply is probably tripping because the main circuitry wants more "power" at start up than can be given .. which could be because of a problem in that the power supply has a fault and can't give .. or that another circuit is faulty and is demanding more from the power supply than it was designed for ..

Some companies sell replacement boards once you realise where your problem is

From experience, unless you go to the manufacturers workshop, a repair will take some time to figure out and fix. The manufacturers usually have spare boards that they use for trouble shooting which means that they swap out boards until the set starts working, then start replacing the boards again ..
If it's a well known fault they will know what to do ..
If you go to an independent repair guy he will have to diagnose everything, starting from the power supply and working through different boards until he finds the problem.
If he has had a set like it before , it will be quicker, but since you say it's possibly an import then it's quite likely that it NOT be an easy job .. all depends upon whether its independent modules or a single board, what experience he has etc also what sort of components will be found to be faulty .. it may be something very simple .. but more likely it will be age related .. If it's capacitors then he will need to source them, .. on one motherboard that I get in frequently for repair I have to replace a minimum of 22 capacitors each time .. that takes time .. then I have to test .
If the problem is due to inverter or display panel, It won't be a cheap repair .. in fact it's usually cheaper to buy something new as a replacement than repair it.

I would start asking around the repair shops if I were you , but again you probably won't get much of a useful answer. I and a lot of my colleagues have been caught out far too often to put a "price" on a repair. Sometimes there is a secondary problem hidden by the original problem that shows when the equipment comes in .. we fix the obvious but then find the hidden .. that can make or break the possibility an economical repair! and that's why we refrain from putting a price on something that is unknown. Sometimes it can also take several days tracking down components only to find that due to scarcity , the price may also have jumped from $10 to $100

craigwatanabe · 06-26-2008, 04:02 AM

One of the good things about LCD tv sets is that unlike CRT or Plasma, there are no high voltage transformers inside a LCD tv set so there is no worry about high voltage arching. However there is still the line voltage that can kill you (same voltage that powers your toaster).

As for the LED changing colors like a Christmas tree, I'd say it's the power supply as well. In that case it may not be worth it to buy it.

06-11-2008, 11:25 AM	#1 (permalink)
Jolo Registered User Join Date: May 2007 Posts: 39 OS: Win XP Pro	Can't identify the problem with my lcd tv Hi Guys! Im planing on buying a cheap, really cheap, lcd tv. The reason for this being so prizey is that the person selling it can't identify the reason to the tv malfunctioning. nevertheless, ive tried searching the web but with no sucess, so thus im contacting you guys. i know you're far better than me at finding the right information. So the problem is as follows: When the owner of the tv starts it, the diode that's supposed to be green shifts from green to red, back o green, to red etc. - flickers between the two. There is neither picture nor sound. The brand and model of the tv is: Stevison 2661 (32 inch) im from sweden and there's no such tvs here so maybe its imported from the states or england. i would apreciate any kind of information about the tv or, at best, an answer to what is wrong with it. best regards jolo Last edited by Jolo : 06-11-2008 at 11:27 AM.

06-11-2008, 03:08 PM	#2 (permalink)
Done_Fishin Moderator Hardware Team Join Date: Oct 2006 Location: Brit living in Greece Posts: 4,906 OS: Win ME, Win XP Pro SP3, Ubuntu 7.04, Mepis 6.5 My System	Re: Can't identify the problem with my lcd tv The TV is probably (but not limited to) having problems with the power supply. the possibilities are that 1 .. the power supply is having problems starting up due to a fault within the supply 2 .. the power supply is having problems starting up due to excessive load causing it to trip out. I do not know the particular brand or model, but experience dictates that the best place to start search is by thoroughly examining all areas of all boards for swollen or leaking capacitors. Anything that looks like it might be anything other than a perfect flat topped capacitor is suspect and should be replaced with a capacitor of the same type, voltage , capacity and temperature rating. I prefer to change all capacitors that are 85 degrees celsius for 105 degrees celsius. If a capacitor needs changing but you can't find something of the same value and voltage rating .. ALWAYS take the next value larger .. so if you have a capacitor that is rated 6.3Volts .. but can't find one .. use 10 Volts or more NEVER use one that is rated less than the original .. it will fry very quickly ad probably cause a few more problems as well! If you need a 270uF capacitor then a replacement would be 330 uF or even 470uF. Take care not to go too high .. that can cause other problems too . Preferably, if you don't know about Electronics, DONT OPEN THE TV AT ALL!!. There are lethal voltages inside that can kill even if the set is switched off! __________________ D_F How to mark your thread as solved

06-12-2008, 03:40 AM	#3 (permalink)
Jolo Registered User Join Date: May 2007 Posts: 39 OS: Win XP Pro	Re: Can't identify the problem with my lcd tv hi again, and thanks for the quick reply. the thing is that i dont know anything about hardware in a tv, sov thus i guess that my only option is to leave it to professionals. however, two questions comes to mind , 1) how likely is it that the problem has to do with the power supply? very likely, like 90%? 2) How difficult is such a procedure for an expert, i mean - will it cost me a fortune to have them fix it for me or is it quite easy to fix, and thus quite cheap? cheers Jonatan

06-12-2008, 11:26 AM	#4 (permalink)
Done_Fishin Moderator Hardware Team Join Date: Oct 2006 Location: Brit living in Greece Posts: 4,906 OS: Win ME, Win XP Pro SP3, Ubuntu 7.04, Mepis 6.5 My System	Re: Can't identify the problem with my lcd tv Since I have no idea at all of what is inside this particular model .. I just couldn't say .. Point is that the power supply is probably tripping because the main circuitry wants more "power" at start up than can be given .. which could be because of a problem in that the power supply has a fault and can't give .. or that another circuit is faulty and is demanding more from the power supply than it was designed for .. Some companies sell replacement boards once you realise where your problem is From experience, unless you go to the manufacturers workshop, a repair will take some time to figure out and fix. The manufacturers usually have spare boards that they use for trouble shooting which means that they swap out boards until the set starts working, then start replacing the boards again .. If it's a well known fault they will know what to do .. If you go to an independent repair guy he will have to diagnose everything, starting from the power supply and working through different boards until he finds the problem. If he has had a set like it before , it will be quicker, but since you say it's possibly an import then it's quite likely that it NOT be an easy job .. all depends upon whether its independent modules or a single board, what experience he has etc also what sort of components will be found to be faulty .. it may be something very simple .. but more likely it will be age related .. If it's capacitors then he will need to source them, .. on one motherboard that I get in frequently for repair I have to replace a minimum of 22 capacitors each time .. that takes time .. then I have to test . If the problem is due to inverter or display panel, It won't be a cheap repair .. in fact it's usually cheaper to buy something new as a replacement than repair it. I would start asking around the repair shops if I were you , but again you probably won't get much of a useful answer. I and a lot of my colleagues have been caught out far too often to put a "price" on a repair. Sometimes there is a secondary problem hidden by the original problem that shows when the equipment comes in .. we fix the obvious but then find the hidden .. that can make or break the possibility an economical repair! and that's why we refrain from putting a price on something that is unknown. Sometimes it can also take several days tracking down components only to find that due to scarcity , the price may also have jumped from $10 to $100 __________________ D_F How to mark your thread as solved

06-26-2008, 04:02 AM	#5 (permalink)
craigwatanabe Registered User Join Date: Jan 2008 Posts: 252 OS: xp	Re: Can't identify the problem with my lcd tv One of the good things about LCD tv sets is that unlike CRT or Plasma, there are no high voltage transformers inside a LCD tv set so there is no worry about high voltage arching. However there is still the line voltage that can kill you (same voltage that powers your toaster). As for the LED changing colors like a Christmas tree, I'd say it's the power supply as well. In that case it may not be worth it to buy it. __________________ A computer is only as powerful as it's user so build wisely.