This set was dead. IC 601 DP704C in power supply was burst. After replacing this IC, montior shows faint horizontal lines along with display. These lines are somewhat like we see when the monitor is in interlace mode. Is this due to filtering problem?
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Back - light problem. Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis. http://electronicshelponline.blogspot.com/
To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement.
Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. http://electronicshelponline.blogspot.com/
Type in the brand name of your device, in the search box [at the top right] of the display window. It will make surf easy.
Monitor horizontal lines problems usually caused by a defective vertical output/driver ic. A missing supply voltage to the vertical output ic may caused similar faults which is one horizontal line across the display. Dry joints and missing vertical output pulse from vertical oscillator ic also could contribute the same symptom. If you discovered that the protection resistor (usually from 1 to 4.7 ohm) open circuit or burnt, then replacing it won't solve the problem. The resistor burnt or open circuit was due to a short in the vertical output ic. Thus you have to replace the vertical output ic and the burnt resistor together before you switch on the monitor.
If a single inkjet in your printer is not functioning then output will appear as a horizontal line across the page. If one of the jets is on all of the time then output will have black or colored lines across the page. Use the following steps to isolate the problem:
- Replace the ink cartridge
- Check the flexible cabling for continuity and for short circuits between adjacent conductors
- Exchange the control board for a good one
- Finally check the power supply
You may have one of two problems. A vertical one in which you may have horizontal lines across the top of the screen. Or one bright centered horizontal line. The fix here is to resolder the vertical IC and replace the capacitors near and next to the vertical IC. The second problem would be the dead set. In this case , the power supply will need reworked. You will need the following components. Replace the powerline regulator STR53041, the regulator N4923 and capacitors of these values, 25 volt at 100 MF and a 35 volt 22 Mf. these components are near and next to the regulator STR 53041. Now,next to or in front of the flyback transformer there is a small cap at high voltage...I believe this one may be a 200 volt at 1 or 2.2 Mf. replace this, and the other capacitor near two heat sinks on the edge of the board in front of the vertical IC is a 25 volt 220 Mf cap that is also dead. It has been a very longtime since I have repaired this one. But the information, will get your TV up and running again! Find an electronic hobbiest or a TV tech to repair this for you. This info will help you get a reasonable repair bill. Thanks for asking and show a few hands of support.
Now ur tv still get a solid power LED light?Yes,only few colors strip lines show up,mean ur tv board that call the T-CON decoders board is dead.This T-CON decoders board sit in the niddle bottom of the LCD screen panel.Tries websites like Shopjimmy.com,Ebay.com to buy a refurbish T-CON decoders board for the replacement.
Your described problem indicates failure at the vertical deflection circuitry. Almost always, this would be a defective vertical IC. In some instances, this could also be caused by the absence of Vcc (supply voltage) to the said IC. This is a relatively easy/quick repair. What would be more challenging is identifying the IC, removing it, and replacing. Replacement would be readily available from most electronics part stores including Radio Shack.
The faint white lines at the top of the screen is the warning that the pump-up capacitor in the vertical output circuit is going bad and the output itself is about to short out. When the TV stops working, the vertical output IC has finally shorted out. Replacing the vertical output IC, the pump-up capacitor and possibly a small value resistor next to the flyback (B+ for the v-out) should bring the set back to life.