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Repairing Samsung 153V LCD Monitor With Dim Display

by:Teeho     2020-06-09
One of your common problems in Samsung 153v LCD Monitor was display bluish. If you get closer into the screen you need to to comprehend the display under dark environment you actually could look at the display within the was very dim. Products and solutions press leading panel button, the on-screen display (OSD) would appeared and this proof that the main board, driver board and LCD panel is working and the problem consistantly improves inverter ship. The function of inverter board is produce an ac wave from dc voltage to switch on the lamps which was located on top and bottom of the LCD Monitor. If the inverter board has problems it would not light inside lamps exactly what you could see only a dim depict. I still could recall when I first encountered such problems long time ago and associated with lack of information, I could not solve it. I have done call up my repair friends to asked about the solution but no one able to give me a fix. Even if you surf the internet for 'Samsung 153V LCD Monitor dim display repair', you is not going to find them. Due to this I should do my own research to obtain the answer and I've never give ascending. Winston Churchill once said 'Never, never, never give up'. I'm releasing the solution only to my loyal members or subscribers only-thanks for your support. Let's begin immediately! Once the cover as well as the internal aluminum casing were opened I saw two bulged filter capacitors in the secondary side of switch mode power source. The value was 470 and 1000 microfarad 25 volts. I saw four more electrolytic capacitors located at the inverter board have changed color and also the value was 47 micro farad 25 volts. Browsing through the whole board with my ESR meter Identified another capacitor faulty (220 uf 25 volts) which was near the fuse (3amp). Since this capacitor was located at the same line with the fuse, I presumed that the fuse can provide way as well. True enough, checking the fuse with an ohmmeter revealed that it has open signal. Now, actual truth is that problem faced by many electronic repairers who addresses this model was, after replacing most of the components on top of the LCD Monitor still examine work-it's still dim! Initially you have to ask yourself why the fuse blown? Could it be caused along with defective capacitors or something shorted at night fuse variety? The nearest circuit to the fuse was the start circuit that consisted of one pair of NPN and PNP digital transistor (4k7 +4k7 resistor built in the transistor). Additional LCD monitor designed used the involving C945 and A733 in start program. By the way the part number for Samsung 153V start circuit transistors were the A6J (PNP digital transistor) and the A8J (NPN digital transistor) as shown in photographs. Sometimes only these transistors have problems (shorted) that caused the fuse to blow however in the above case both digital transistors are tested okay. Since both transistors were working, now the concentration require to be in usual ic's that drive worth voltage transformers because the 12 volts voltage was supplying to all of ic's. These 4 ic's have many part numbers and the most typical one that the manufacturer used was 4532m. Some board used the AD4E10 and BBD3N13 part number. Right this moment it is very hard to access the datasheet or technical specification for this number even from the web search. Do guess what happens is inside these IC's? It is actually a pair of P-channel and a N-channel mosfet built there. And do you are aware it can be test along with a meter? Yes, if you employ the Peak atlas component analyzer, it would prompt for you the direct result. From the result what a person are N channel FET located at pin 1 (source), pin 2 (gate), pin 7 & 8 (drain and both pins joint together internally). As for P channel FET, pin 3 (source), pin 4 (gate) and pin 5 & 6 (drain and both pins joint internally). From the above test Observed two this kind of ic's have shorted. Replacing these two shorted IC with the capacitors and fuse put the LCD Monitor back one's! One more thing I'd like to share at this model could be that the inverter PWM IC BIT1305 was quite robust and rarely gave problem.
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