I have a LG CT-34M20ET that has a problem with focusing, blurring picture, I have played with the contrast, and flyback transformer adjustments, no differing in picture, any possible suggestions would be handy.(electronic technician I know TV's can bite)
An expert who has achieved level 2 by getting 100 points
An expert that got 10 achievements.
An expert that got 5 achievements.
An expert whose answer got voted for 100 times.
Re: TV focusing problem
It's good that you know how TV's can bite, I'll still have to post this in case someone having your problem and reading isn't aware of this and feels lucky-
If still under warranty or if you have no electronic repair experience you should take the set back to the shop or to a repair person. Some of the solutions described below can be dangerous, TV's are very hazardous to service. Even when plugged out, TV's can store very high voltages.
could be a problem with the screen potentiometers block. should be located on the chassis close to where the HT lead passes on its way to the picture tube.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
blurred picture can be adjusted,and sometimes replacing of crt socket will solve the problem.
this is tricky so i've advice you to follow what i've said strictly.
Open the back cover of your set (make sure that you unpluged the unit first).
Look for the flyback transformer (it has a sunction cup connected to the picture tube).
You will see an adjustment knob on it, it mark focus but wait before touching,mark it with your pentel pen,marking the original location of the knob is important because that is the factory align.
After marking get an screw driver w rubber insulator as a handle to avoid an electric shock,this will be used to adjust the focus on the flyback knob.
Turn on the unit and hooked it up by your dvd player.
Play the dvd so that you will see a picture on the screen.
Pause it with a picture with characters.
Now you can see the blurred picture?
Try to adjust the focus on the flyback back and forth minimal turn only.
There's a reaction?Yes- continue to get a perfect picture and youre done.
There's a reaction?No- back the knob on its original position.
Your crt socket is faulty.
try some helped of your technician or people knowledgeable of disoldering and soldering technique.
Pull the board on the crt socket.the socket which attached to the tube is the one you are going to replaced. I've adviced you to observe first and familiarized what are going to dis-assemble because you will do the same when you replaced a new one.
After replacing your crt socket,picture ok?Yes-you're done
After replacing your crt socket,picture ok?no-picture tube is faulty.........
This sounds like low screen voltage(A1)try adjusting the a1 voltage bottom control on flyback transformer if you have a voltmeter, voltage on crt base possible market screen or A1 shoud be beteen 350/500 volts when making adjustment remember to take into account current taken by meter If voaltage will not adjust flyback transformer will have to replaced
Six to seven years is about the usual life of a picture tube, and then you start seeing signs of aging. Poor focus is one common symptom (the loss of crispness you noticed). There is an internal focus adjustment, but it usually can't compensate for the tube. If you want to try it, the control is on a part called the flyback transformer. It's usually found on a rear corner of the circuit board, and has a red wire going to a rubber contact cap on the picture tube. Most flybacks have two little knobs on them, and you want to tweak the one marked "FOCUS" a little to see if improves the picture. BE VERY CAREFUL! WITH THE POWER ON THERE ARE POSSIBLY LETHAL VOLTAGES EXPOSED!
If the focus adjustment doesn't help enough, it's time to look for a sale on an LCD monitor. The prices have come way down, and eBay is a great place to look for deals if you don't want to buy new.
If this just happens while vcr is playing. Check the vcr. Did you happen to adjust its brightness and contrast settings. If things doesn't change. Then if this model is a crt type could be adjustment on its flyback transformer is needed tweaking slowly its screen knob or tweaking also its focus knob until you got it to the level of viewing it correctly.
But be aware, hazardous voltages inside it. Or let th technician set it for you, its a minor adjustment.
hi there, its a decousing problem, look for the connection of the decousing which is connected behined the pic tube to the board. check some electronic parts, it may be temperature resistor, termistor, transistors, capacitor, etc.ty
If you feel good about opening your set then you can try this: Look for the flyback (high voltage) transformer, with the thick red wire which goes to the top of the picture tube. There are 2 controls on the flyback transformer, focus (top) and screen (bottom)Turn the brightness and contrast all the way down and then increase the screen control until you see retrace lines, and then back it down until those lines just vanish. Return the brightness and contrast to normal and adjust the focus control, if necessary, for a nice sharp picture. Let me know if that brings your brightness back.
Flyback transformers usually have 2 adjustable rods - 1 is for focus the other is for screen (G2) voltage. try turning Clockwise the Screen adjust with brightness-contrast at max. Till you see white diagonal lines, then go back until the lines disappear - then tune the brightness to your desired level.
the neck board of the monitor needs tube replace it is corroded with carbon if you cannot get a replacementbuy a new monitor.but also check the flyback also it could be faulty replace it check www.dalbani.com for your monitor parts or repairworld.com,good luck.