You will need
- tester (multimeter);
- two lamp 60-100 W;
- - soldering iron and solder;
- - screwdriver under the cross;
Malfunction of the TV can be very different in nature. If it is when you enable the do not signs of life, first check voltage in the socket. If it is, unplug the TV from the mains, remove the back cover. Then check the power cord of the power supply and switch. In that case, if the voltage supplied to the unit power, we can assume it to malfunction.
First, carefully inspect the power supply. Pay attention to the darkened resistors and swollen capacitors. A healthy condenser the tip of the flat – if it is swollen, it can be assumed that he punched. Do not forget to inspect the opposite side of the Board. Check if there are breakdowns between tracks are properly soldered parts. Externally the power supply is OK, inspect the unit horizontal scan – it is the most loaded, malfunctions occur quite often.
In that case, if external inspection of the units of TV are not allowed to reveal the fault, to begin her search should check the supply voltage of the power supply. Most likely, you don't have a schematic of the TV, so find it on the Internet. According to the diagram to determine which connector of the power supply goes to the output stage line scan, and disable it (look for voltage 110-160). Instead, plug an ordinary incandescent bulb of about 100 watts.
If a separate connector no need to unsolder one of the elements of the output circuit of a given voltage on the power supply and to connect the lamp. When you first turn on the power supply unit is also connected via a second lamp. In that case, if it is brightly lit, the power supply has a fault. Check the chart to see which elements of the PSU may be faulty (broken) and directly passed through a current to the lamp.
The situation when the bulb lights up and then goes dark or poorly lit, speaks about the serviceability of input circuits of the power supply. The lamp at the entrance you can disable and a further test carried out without it.
Check power supply start by measuring the voltage across the load (the connected lamp). Check the chart to see what voltage should be present. It can be specified as connector of the power supply and the control points. The supply voltage can be provided at the output of the primary winding of the flyback transformer. It should be in the range of 110-150, depending on the size of the TV screen.
If the voltage is much higher, around 200 To check the elements of the primary circuit of the PSU, responsible for its formation. Pay particular attention to electrolytic capacitors. Externally serviceable, but the old capacitor may have a low capacity, which leads to the increase of the output voltage. With reduced need to check the secondary circuit power supply. Pay attention to the capacitors and diodes in circuit horizontal and vertical deflection.
In that case, if all voltages are OK, the fault should be sought in other units of the TV. First in row scanning.
Remember that in running there are high voltages hazardous for life! Do not touch the tube and its feeder circuits.