Slow to switch on then cuts out after 5 mins
This sounds like a very common issue.
If set is hard to turn on (takes several tries)but will eventually turn on hereis what my guess would be.
Every set has a standby power supplythat is running 7/24 if the set is plugged in and it supplies voltage to theremote circuit that turn on the main power supply for the tv and hence turn theset on.
This is an area where companies cut corners by using lower rated voltage caps.By this I mean Standby usually provides under 10 volts to trigger the seton----what they do is use filter caps rated at say 10 volts max in a circuitwith 9 volts (example)=with the standby on all the time the filter caps(electrolytic caps) dry out and fail.
The problem usually begins where you have to turn set on or or two times andgradually gets worse--takes longer and more tries to get it to come up.
Once on it will stay on until turned off for a period of time.
The caps will begin to work better (regain some of thecapacitance) as they get hot--hence one it is on it will seem ok.
The beauty of this problem is most of themhappen when set is a year or two old (no warranty) and all you have to do islook at the top to locate bad ones.
They are generally black or blue and round and vary in --they have twoconnections each--a + for positive and a - for negative--not unlike a batterywhich in a way they are. The + and - are marked on top and bottom of most boards.
They are easy to replace and not expensive parts.
The tops are silverand metal looking with creases on top and if bad they will be puffed up ontop---tops must be perfectly flat with no brown material leaking top or bottom.
If this is your problem once you id them (make a drawing) you can begin.
Here is the critical part---on each cap is also marked the value like 220uf 10vdc---220 micro farad at 10 volts maximum.
If you find for example 6 puffed up and all are 10 vdc replace them with thesame value capacitance (like the 220 uf) but go up to at least in this case(from 10 volts) to a 16 or higher rated voltage cap.
The only issue is when you go up in voltage rated value the cap is larger sosometimes there is an issue of physical space for the replacement on the boardto fit them in.
The reason they cheapen these sets in this way is if 10 caps and you make25,000 sets there is a considerable savings in parts cost.
They do not care as long as it lasts past the usual one year parts warranty.
I have taken the time to be long winded because this really sounds like it maybe the problem you have.
See attached photo of a typical cap and if you have questions or need advicelet me know.
SOURCE: TV switch off randomly
It is a Rely in the Power Supply. Need to have it changed out. Cheap part.
SOURCE: T.V Problem
I think your main power supply is failing.
If you want to avoid a long interruption or fix the problem now, read my stock response paste below:
If
it's failing to turn on reliably, the main power supply is probably at
fault and without some technical background and a couple of test instruments,
you will not be able to do the repair yourself.
What you can do though is; unplug the set, let it
stand overnight or at least several hours, remove the back panel and look for a
separate board with mostly larger components on it; it will have a ferrite core
(no laminations as with a line-frequency part) transformer on it and several
larger capacitors which are cylindrical and mounted vertically to the board.
Before touching anything inside, especially on
that board, allow several hours to be safe since the larger capacitors can hold
a painful voltage charge for some hours.
If you see signs of overheating such as
discoloration of the board material, it may not be repairable but if you can
find a part number on the board, you might be able to buy the power supply and
install it yourself but it will likely have the same problem eventually unless
they have altered the design.
If there are no signs of heat damage to the board,
there may be companies offering to repair it as a subassembly instead of
repairing the whole set which could be much more expensive.
If you choose to replace or have it done, the
power supply still may not be at fault since most are capable
of switching on and off if a downstream problem is causing an overload.
SOURCE: on off switch keeps flicking .tv takes 5 mins to
power light keep blinking on and off no power
SOURCE: problem switching on and off
samsung will do a free repair i had the same fault and they fixed it fir free give them (SAMSUNG) a call.it is a known fault
SOURCE: samsung LCD 40" TV I have a problem with 3
hi,
There is problem with the back light of your tv. In LCD tvs CCFL are used as back light to give light to independant pixels.There are about 12 CCFL lamps in 40 inch lcd tv. All CCFLs are laid horizonally behind the screen. If any one of it dosen't light then that portion of the screen will dark. There are two cahnces for this problem 1. The CCFL lamp faulty (Rare) , 2. The high voltage inverter. CCLF lamps required high voltage to light. This high voltage is provided by the inverter board inside ths tv. If any one of the chopper transformer (high voltage transformer) have some problem then the CCFL lamp which driven by that transformer will not light. You have to check the 24V from the power supply. If its ok the you have to check the inverter board.if avilable replace the same. if you are not able to do the same i will prefer to consult some one experienced in it. Back light inverter board will look like one in the picture. If you need any more assistance from me feel free to contact me by FixYa.
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OK
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