Light blinks three times on my sony wega tv model #kv-32hs500 but will not come on .
Three times blinking denotes that there is some overvoltage in the secondary DC supply rail inside your TV. It is called Over Voltage Protection [OVP]. Due to this fault as soon as the set is switched on, it goes to standby state and the front LED blinks tree times, and won't come up again.
It may be due to power supply regulator section fault inside your TV. To find out you have to open the back cover of the TV. As high as 32KVDC [32,000 volts DC], points are there inside your TV, while it is working, all care should be taken before open it. Even though the TV is switched off, the final anode of the picture tube will have a charge upto this voltage for sometime and it is dangerous. So be care.
After opening the TV, locate the power regulator section. It can be easly located, that the AC input goes to that section, after the switch connection. You have to pull out the printed circuit board and should keep it upside down for repair work. During this time, sometimes you may have to unplug some plugin connections from the board, and keep it marked, so that you have to refit it there later. You must have some concept of soldering and more patience to do this work.
After the board has been pulled out, loate if there is any soldering loose contact to the regulator Ic or its nearby components. As they will heatup during working, continous heat up and cooling may make some of the solderings, and it is normal in practice. As it is very difficult to locate the loose solderings by naked eye, resolder all suspected points with applying a little bit of extra solder. Never make any short between them while soldering. Normally this will rectify the problem. If it does not help, replace the power regulator with same type and number; [ Normally in Sony sets they uses STR type regulators on power side], and it is a very stable and High Accurate device, and should be replaced with the same type and number.
Check if now the secondary DC voltage at the secondary voltage rail of your Tv. Now it will be zero due to overvotage shutoff. Locate the pin to which the DC power goes into the LOT [Line Output Transformer], and make a small break on its print that carries supply to it. Be sure to make a small break, as we have to rejoin it after the fault detection. Connect a 100W filament type bulb between the DC supply Rail and to the Negative. Switch on the set. The bulb will glow, and take the votage across its filament. It should be between 125 and 130VDC, for 32" Sony TVs. if it is found abnormal, you can make sure that power regulator section has some trouble in it. Three blinks shows that symptom in Sony TVs. Ok.
Oct 31, 2010 |
Sony Standard (CRT) Televisions