NM2168(020731) 14" TV. Vertical circuit

The vertical deflection circuit of your tv has a problem.
First, try to replace the vertical ic. This ic can be found near the plyback or horizontal section. It is a linear ic with heatsink.
If nothing happens after replacing the ic, replace all the polarized capacitor near the ic and resolder the components at the vertical section.

Hello
It may be due to an Integrated Circuit [IC] fault. Your TV has lost its vertical sweep, and the is why you see a norizontal bright line across the center of the screen. All TVs has bot Hotizontal and Vertical Sweep to spread picture on the screen. When Vertical sweep fails, you will see a horizontal line, and when horizontal sweep fails you will see a vertical line at the middle of the screen.
n your TV, most likley the vertical Ic is faulty. This is a common phenomena in almopst all telivisions. The said IC is diretly soldered into the circuit board inside your TV. To replace it you have to open your TV. Take all precautions before opening the back cover of your TV. You are going to work with an electrical equipment, and keep it in mind always. After opening the back cover, just locate where the Vertical Output Ic is. It will be normally screwed to a heatsink plate, inorder to radiate heat from it while working. You can locate it by the following method. Different TV circuits has different positions to this Ic. Just look on the Deflection Yoke [the coil fitted on the neck of picture tube]. From there four wires will go to the main printed circuit board. Out of which two of them will be thick, and other two will be thin. The two thin wires are the carriers of vertical sweep from main board to deflection yoke. Follow the the two thin wires. You will see it to be pluged into one point at the printed circuit board. Just upside down the printed circuit board, after pulling it outwards, not disturbing any of the wirings, and look through the circuit track, to which point the tracks goes to. Somewhere near to it you can locate the above said IC.
Just take the main input votage to that IC. It will be normally 18v to 35VDC. You must have multimeter to measure this voltage. If the voltage is there, look for any loose solderings over there to the legs of that IC. If there is any soldering loose, the IC will not work properly, and vertical sweep loss will be the result. If there is proper voltage check the voltage at the output pin of that Ic. It should be almost half the voltage of the supply voltage. If it is not there, make sure that the IC has damaged.
Resolder it out from the board, and go for a same type and number. Replacing it will solve the problem. Normally vertical output ICs are not very cosltly. Here in India, all types of vertical Ics will have a price rate between 80 to150 Indian rupees, that is upto four American Dollars. Ok.

Assuming this is a TV with a picture tube, it is most likely a vertical deflection/drive fault, caused by a number of components including (but not limited to) the vertical IC. Dry solder joints and/or hairline fractures within the copper tracks on the board can cause the vertical collapse as well as leaky diodes and faulty resistors. (dry joints are usually the most common causes of circuit failure - before component failures) Non-electrolytic capacitors which are also in the vertical stage can affect the output when they fracture.

** It would be a good idea to check the board thoroughly for dry solder joints before considering replacement of any parts on it. **

Unless you are tech. savvy, and have some experience with electronic circuits, particularly TVs, this is not something you should try to repair yourself. Send it to an authorised repair centre for a quote and second opinion, then make a decision afterwards - up to you.

This is a problem with the vertical circuit and is usually a defective vertical IC. If you can solder, locate the vertical IC (small flat IC attached to a heat sink with about 9-11 pins). Try resoldering the pins on the IC. If that fails to resolve the problem, replace the IC. This IC will be marked LA7837 or something similar. Keep us posted. Dan

Hello jpm1lo, your problem needs someone with some repair skills to assist you, firstly your TV has both a horizontal and a vertical circuit,your problem is in the vertical circuit. The IC (integrated circuit) in the vertical area should be changed together with the 2 or 3 cylindrical capacitors ( number will vary in different brand names) also in the same circuit. This will rectify your problem.....Rudney

This is a vertical circuit problem that is either bad connections on the vertical IC or a defective IC. If you can solder, you can fix this yourself. Look for a small flat IC attached to a heatsink with about 9-11 pins. It may be marked LA7837 or something similar. Try resoldering the pins first. If that fails to resolve the problem, replace the IC. There may be defective caps in the circuit as well, but those don't usually cause complete vertical failure. If the picture does not return fully, update this and we'll continue on to the next step.

Dan

This is a sign that there are either bad caps in the vertical circuit or bad connections at the vertical IC. CAn you solder? If so, resolder the pins on the vertical IC first and post the results here. The vertical IC will be a small flat IC attached to a heatsink with about 9-11 pins. It may be marked LA7837 or something similar.

Keep us posted.
Dan

i would like to know the model# of the tv..

thanks

This is a problem with the vertical circuit and can be either bad connections at the vertical IC or a defective IC. This is a common problem and is easily repaired. The vertical IC is a small flat IC attached to a heatsink with about 11 pins or so. It might be marked LA7837 or something similar. If you can solder, try resoldering the pins on that IC first. If that fails to resolve the problem, replace the IC. Expect the IC to cost about $15-$25 depending upon the exact one. It is possible that some of the capacitors in the same circuit are defective as well. Once the IC is replaced/resoldered, report back here with the results and we can go further if necesary.
Dan

You have an intermittant vertical sweep circuit! It could be the vertical out put IC solder connections on the printed circuit board, or maybe the IC itself has poor connections between the IC and the contact legs that mount the IC, or another componet in the vertical sweep circuit. If you know how to solder and unsolder, work on printed circuit boards, then you shoul have no problem replacing the vertical sweep circuit. Good Luck