TV problem The TV is coming on standby but the screen does not light.I tried to check the line transformer and the line transistor and i found them good.tell me another solution.

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.
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Hi Hashim.
EHT (Extra High Tension) usually reefers to the 24kv to 30kv, focus and first anode (A1) voltages required to operate the crt (picture tube). These voltages are supplied by the line output stage, primarily the line output transformer (often refered to as the flyback transformer). This transformer steps the voltage up to 8kv and an embedded rectifier trippler circuit tripples this to 24kv dc to supply the final anode voltage to the tube (Hence the big rubber cap and thick cable.
The line output transformer is driven by a smaller transformer (line driver transformer) via the line output transistor.
The driver stage is fed by the hoizontal oscillator circuit.
So we can see that a failure in any part of this circuitry will most often result in no picture. The line output transformer is the heart of the system, it not only supplies the EHT voltage it also has to
supply an LT voltage for the vertical output stage but also the sound output stage.
A Fault in the A1 circuitry would result in a very dark picture but sound ok. Or the picture badly out of focus.
The line output transistor going short circuit results in no picture and no sound with the set shutting down to the standby mode or
hic upping (making a ticking noise. This problem would be amongst the most common and is easily confirmed with an Ohm meter. The line output transformer itself can develope an internal short with the same results (less common). Failure of the line oscillator and driver stages are most easily confirmed with an
oscilloscope. A fault in the power supply will also give these symptoms. To confirm line output stage is functional look to see if the tube heaters are glowing, this supply also comes from the line output transformer. Can you feel the static if you run the back of your hand across the front of the screen (often feels like running your hand through cobwebs. this would indicate that the EHT is present and the fault is elsewhere. Understanding how something
works enables you to find out why it doesn't. If you have occasion to replace a short circuit transistor, be sure to reslder all pin connections to the line driver transformer. I've found dry joints here
to be a cause for random inttermittent failure of this transistor,
Best regards from Vintie.

Hello
Along with the flyback transofrmer, its horizontal output transistor also must be replaced. I don't know whether you have replaced it or not. If not, replace it too. It can be located very near to the flyback transformer, a three terminal component, black in colour, usually screwed to a metal heatsink. Then switch on the TV and measure the video output voltage at the video output card pluged directly to the picture tube neck. The collector of the video aoutput transistors must come around 145VDC. If it also is there, advance the screen control on the flyback transformer to get a raster. If that voltage is not there, it means that the flyback transformer is not working, and horizontal oscillator stage should be checked for oscillation, check the lined drive transformer for its primary winding open, Check the entire horizontal oscillator section. The collector point of the line drive transistor, the transistor that drives the line drive transformer, a small transformer soldered diretly to the printed circuit board; should be checked with frequency meter. The frequency at that point should come around 15525HZ approx: OK.

check your horizontal transistor maybe it's shorted replace horizontal transistor or maybe the fusible fuses are open check for open resistors at the horizontal section of the circuit.

check the power supply, its not giving out the required voltage output. if you cant repair a tv plse take it to a workshop, ask a technician to make sure that he checks the following components.
power diodes and transistor, fusable resistors around the power supply, and zener diodes.
he should make sure that an ht of 95-110 volts appears on the line transformer. later a transformer will produce various voltages to trigger other voltages to open up your tv. thanks

if you cant repair a tv take it ot a w/shop and have it checked. let your tech check that an ht voltage of 95-105 is reaching a line transistor, also a transistor be checked for leaks, also let him check a line transformer, and the surrounding tin capacitors for leakages and change of values.

check the line transistor near the line transformer
and make sure that 90-115 volts is reaching a transformer.

Hi there!

You have an obvious error state on the unit. You may want to try and remove the Line Transistors to check for voltage first. In the region of 145V(between base and collector. If the set then stays in standby you may have a vertical error. Also check 5V rail to the processor and suspicious looking components like caps. Good Luck,JUS004

check secondary voltages and horizontal out put section, and check smps and all the voltages and line out put transformer section...

This is like a car running without a driver,the horizonatl output transistor has the voltage it needs but it does not have horizontal drive signal applied to the base of the horizonatl driver transistor,the driver transistor should have a signal coming from the signal processor where the signal is generated just to get give it to the driver this driver then it gives it to the output to energize the flyback and light up the picture tube and generate a few other supplies,158 volts are there because the output is not turn on,try measuring voltage somewere else in the set and not at the collector of the output,there is a b+supply that goes to the signal processor(8 to 12 volts),check to see if you have this voltage,I couldn't tell you the pins in the siganl processor IC without squematic,It seems you know your way around tv service but be careful when checking voltages.Let Us know if you need more information.