Problem - Sony Bravia KDL-46NX800 two flash diagnostic - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 2 Old 12-30-2011, 02:59 PM - Thread Starter
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Hi, I purchased my Sony Bravia KDL-46NX800 television 13 months ago. The TV failed a week ago while I was watching it. The diagnostic light flashes two times, indicating (per Sony website) a "B+ over current protection (OCP), unit goes to the standby mode then displays the 2 blink fault. Could be a short in the power supply of any of the circuits."

I had a technician out to look at it. He tried swapping the power supply board, but the board he brought was defective (naturally). After speaking with the Sony tech support, he told me that the original power supply wasn't at fault but that it was a defective LCD panel, without doing any other diagnosis to confirm that.

My question is, can anybody think of other malfunctions that can lead to this type of response? And/or is there a way to confirm that the LCD panel is defective? I am planning on testing the voltages coming from the power supply once I find my multimeter to confirm that the power supply is actually working right, but any other help would be greatly appreciated! Thanks!
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post #2 of 2 Old 06-30-2014, 08:43 PM
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I know this is an old thread, but I thought I would post this fix for anyone else running into this problem, as most replacement boards are out of stock or cost way too much on eBay.

For those of you with a 2 blink led code, random resets, or other power board codes (can also trigger backlight codes due to voltage problems as these parts fail) here is a common fix that worked for my set when the power board went down.

2 blinks indicates power board fault. The failing parts are power MOSFETs. I fixed my board by replacing MOSFETs Q6101 and Q6102 (replacement part FQPF9N50CF 9 amp, 500 volt can be ordered via mouser) and fusible resistor R6536 (0.47 ohm. 1/2 watt ordered from amazon) on the power board. Be sure to reapply thermal compound when securing to the heat sink. The MOSFETs fail and the resistor blows to protect the rest of the circuit. This fix works on ex500, ex600, nx800, ex700, nx700, ex701, ex710 series sets and others, and is a common failure, the board locations and numbering will be different for other power boards but the same parts fail on many of these sets.
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