I check the power supply circuit it seems all ok because it has normal 115 volts output. i check the hot, vertical out put and other transistor neer in the flyback are all ok. in the first time i switch on i feel the high voltage but after trying again to swith on the relay became much faster to disconnect and high voltage no more.
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Check the power supply.If you have no output from the power supply try to disconnect the power supply from the other circuits ( such as the IF,audio,video,horizontal,vertical,etc.If the voltage at the power supply comes up when you disconnect a particular circuit then that circuit is loading down the power supply and you would troubleshoot that circuit.If after disconnecting the other circuits and the power supply still shows zero,then you would troubleshoot the power supply.
Hello
You are seeing vertical retrace lines on the top of your TV screen.
There are mainly three causes for it. I don't know the age of your TV. The first cause is due to the supply voltage lack to the video output state. You can check it on the picture tube base card. You haven't mentioned about the diamension of your TV screen. So it can be say as a guess. If your TV is 27", the voltage mantioned above will come to about 245VDC. If there is a great voltage loss, check the smoothing capacitor to that supply, will normally come to the value of 10MFD 450V.
The second one is, capacitor related to the vertical output stage of your tv. It is in the circuit board. Normally these capacitors are situated in an area, which will get hot during working. As s result, there is a chance to the value change of their capacitance. It is best to replace all of them, as it may not cost too much. Before desoldering it out, mark the value of each capacitor is best. Normally replacing the filter capacitor 3300MFD or so,to the power supply to the vertical output Ic will solve this problem.
The third is related with the vertical output Ic itself. Just check all the soldering points in the vertical output section of your tv board. Anyway, resoder all suspected soderings by applying a little more solder, as bad solderings to the legs of the Ic or some other components also may the cause. OK.
This is the power supply for your PC, depend on your local country power supply, some country like North US may use 110 V in their daily use electrical stuff and some country like Euro, UK use 240 V.
Your PC power supply is design to suit this 2 type of power input so can be sold everywhere. What u need to do is to make sure your local country power supply voltage and then just switch the input correctly, i think u have done it.
Unless your household electrical service is running at 230 volts, there's absolutely no reason to set your supply for 230. When you choose the 230v setting the supply REQUIRES 230 volts to become operational...Which is not going to happen on a 115 volt service.
Shrinking picture is a voltage regulation problem in the switch mode power supply, Possibly a cap used in the feedback circuit. Or an over current condition on the B+. This is a very tech intense repair because there is no magic bullet. If it is shrinking on bright scenes then you can bet it is a regulation problem, bright scenes draw more current from the power supply causing this effect. I would not suspect the horiz output because the regulation for this circuit usually comes from the main switch mode power supply. One diagnostic is to monitor the B+ going to the horizontal output and see if it fluctuates. If so you can bet it is a cap or optical coupler in the switch mode circuit.
First check for fluid on the PCB's, if ok check the following:
This model is equipped with a self-diagnosis feature to help with diagnosis of shutdown problems. To activate this turn the unit on let it shutdown then press the input/device and menu buttons on the front panel simultaneously and hold them in for 5 seconds after 5 seconds the power LED on the front panel will blink a two digit sequence. This will be one set of blinks a short pause then another set of blinks, this will repeat 5 times. 1 - 2 = no error detected 2 - 1 = X-ray protect (high voltage or beam current) 2 - 2 = Short protect (short protect monitors low voltage supplies) 2 - 3 = Deflection protect (this could be loss of vertical or horizontal deflection) 2 - 4 = Vertical protect (usually loss of vertical from the source) 1. SELF- DIAGNOSIS INDICATE X-RAY. CHECK FOR A SHORTED IC5A03 PART # 270P704010 AND AN OPEN R5A73 82K ¼ WATT OFF PIN 2 OF IC5A02 ON THE MAIN PCB. 2. SELF DIAGNOSIS ERROR INDICATES SHORT PROTECT. CHECK FOR OPEN FUSES F9A04 AND F9A05 PART # 283P043090 ON THE +24 AND -24 VOLT LINES. IF THE FUSES ARE OPEN THE CONVERGENCE OUTPUT CIRCUIT WOULD BE SUSPECT. 3. SELF-DIAGNOSIS INDICATES SHORT PROTECT. CHECK FOR A SHORTED IC4B01 PART # 270P261020 (VERTICAL OUTPUT) LOADING 24-VOLT SUPPLY LINE. LOCATED ON THE MAIN PCB.
Good Luck, big IRISH.
PS If too much call an authorizedservice center and have them give an estimate on their repairs in writing.
My LG tv has suddenly got a problem with the picture. Whilst watching the tv with no problems at all,
the picture was suddenly reduced to a thin vertical line down the centre of the screen
and an awful smell seemed to come from the tv
There is a short ckt in your tv in horl. section.
1 isolate power from horizontal section.
2 check for normal output from power supply.
3 check parts in horl output section
a hor.output transistor
b diode & cap in h/output trnsformerckt.
c check for print.
d if all are ok check for eht transformer.
e if every thing becomes then reconnect hor output section supply.
f put on the set.
This model is equipped with a self-diagnosis feature to help with diagnosis of shutdown problems.
To activate this turn the unit on let it shutdown then press the input and menu buttons on the front panel simultaneously and hold them in for 5 seconds after 5 seconds the power LED on the front panel will blink a two digit sequence.
This will be one set of blinks a short pause then another set of blinks, this will repeat 5 times.
1 - 2 = no error detected
2 - 1 = X-ray protect (high voltage or beam current) 2 - 2 = Short protect (short protect monitors low voltage supplies)
2 - 3 = Deflection protect (this could be loss of vertical or horizontal deflection)
2 - 4 = Vertical protect (usually loss of vertical from the source)
1. SHUTDOWN AT POWER WITH SELF DIAGNOSIS ERROR 2 2. CHECK FOR LEAKY C9A60 470 PF 1000 V PART # 154P400030, PARALLEL TO D9A57 ON THE POWER PCB (NOT SHOWN IN THE SCHEMATIC).
2. SHUTDOWN AT POWER WITH SELF DIAGNOSIS ERROR 2 2. CHECK FOR OPEN FUSES F9A04 AND F9A05 PART # 283P043090 ON THE +24 AND -24 VOLT LINES. IF THE FUSES ARE OPEN THE CONVERGENCE OUTPUT CIRCUIT WOULD BE SUSPECT.
3. SELF-DIAGNOSIS INDICATES SHORT PROTECT. CHECK FOR A SHORTED IC4B01 PART # 270P261020 (VERTICAL OUTPUT) LOADING 24-VOLT SUPPLY LINE. LOCATED ON THE MAIN PCB
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