Re: Samsung LN40E550 Dim Screen
When you first test the diode that was in place, you were getting the reading in both direction so you have to remove the diode to find out if the Diode is bad or not first, but it is tested OK off the board, then I asked you to check the resistance between the two pads of the removed diode and you found that there is 314 Ohms of resistance between the two pads which is not normal (You have to understand and be able to read the schematic to know why that is not normal), then I have you remove the other diode and it is also tested good off the board, but when you remove that snubber capacitor (it is connected in parallel with the diode) then the resistance between the two pads of the diode went up into high resistance so we then know that it has to be the cap is bad with leakage resistance, which it is. The capacitor is an open circuit to DC but conductive with applied AC, that is why when you check the capacitor with the meter it should show open circuit. Notes: Electolytics cap will show low resistance due to the charging of the cap then it will should show very high resistance because Elecrolytics cap has leakage resistance that is why you see leakage current spec of the lytics caps.
Originally posted by browserjoe
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