Changhong LCD TV LT42510HFD troublesome maintenance - android - Phones Developers

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Some time ago, an old user called and said that the TV was no longer available. The Changhong LT42510HFD had no power light. The door check found that the power supply was broken again. I repaired it about two and a half years ago, and changed the TNY277 power IC. [Because the machine does not have a power switch, the user never pulls the plug. I said that you look at it for 5 hours a day. You are working 24 hours a day. In fact, this time. Maintenance has been used for 12 years, it should be said that the quality is good.] This time the power block is directly blown up, the L6599D secondary power management IC is short-circuited, and other small parts are not worth mentioning. The most terrible is a switch. Transformer primary open circuit,
Everyone knows that the most direct way is of course to change the power board, but the cost will increase a lot. Plus the maintenance fee is a few grandfathers. I don’t think it is necessary to repair it. I will tell the user to take a look around. Transformers can not be bought, if it is not possible to change the board, the transformer primary 1-3 double line and around 47 匝, 2-3 single line 47 匝, 4-5 is the feedback power supply single line 17 匝, 7.8---9.10 is more 5 strands of stocks, 5, replaced with Q922, R976, ZD915, R991, Q914, ZD912, TNY277 replaced with TNY280, soaked insulating paint drying machine OK, in order to prevent damage to the transformer again, a 56 in the primary front section of the transformer Ohmic / 3W resistor,
When delivering the user, take a power plug-in board, a few electrical appliances are all plugged in, saying that you don’t have to press the switch when you don’t need it, all have no electricity, it’s much safer.