This fishy smell is caused by the ionization of the air in the TV to produce ozone. The larger the size of the TV screen, the higher the cathode high voltage of the picture tube.
For example, the 31 cm picture tube is about 12000 volts, the 36 cm picture tube is about 14000 volts, and the 41 cm picture tube is about 16000 volts... When the high voltage electrode is not in good contact or is not well insulated from the ground (referring to the potential reference point of the circuit in the machine, i.e. the metal bottom plate), the high voltage of tens of thousands of volts will break down the air and discharge, resulting in ozone. When the situation is serious, you can hear the hissing sound of discharge, and open the back cover to observe the sparks generated by discharge. When it is more serious, the fluorescent screen does not emit light, and even the high-voltage package and high-voltage rectifier tube are burned due to overload.
Methods to overcome high voltage discharge in TV set:
First, make the high-voltage lead in good contact with the electrode of the picture tube;
Pull the high-voltage lead from the high-voltage nozzle located at the cone of the picture tube, discharge the high-voltage nozzle (with a wire) and the high-voltage lead to the ground respectively, then clean the dust in the high-voltage nozzle, remove the rust and dirt at the joint of the high-voltage wire, pull its contact spring outward slightly to increase the contact pressure, and finally put it back to the original place for connection, which can generally solve the problem.
Second, strengthen the insulation of discharge parts;
Firstly, find out the part where the discharge occurs, and then take measures to strengthen the insulation, such as dust removal, padding with glue board, etc. When cleaning the dust, you can use a long soft brush and hand blower (commonly known as leather tiger) to clean the dust. For some dirt with strong adhesion, you can use solvents such as alcohol, gasoline (plastic skeleton and wrapping), carbon tetrachloride, or scrape it with sandpaper and knife. If the discharge phenomenon cannot be eliminated after dust removal, the insulation can be strengthened by padding mica sheet, glue board and other methods. It should be pointed out here that when the picture tube is aging, the weakening of the cathode radiation current will further increase the high voltage, resulting in discharge. At this time, it is best to replace it with a new picture tube.