20 Most Recent Samsung LN46A650 46 in. LCD HDTV - Page 4 Questions & Answers

In most cases the standby light might blink with different rapidity to indicate a fault relevant to the processor. It is possible that most of these indicate that there are errors in the processing section . Since there is a possible short or leak in the circuit the output driver section can take in huge current to trip the SMPS or from advice from the micro processor. Remove the power plugs and make sure that high voltage sections are discharged of the potential stored in capacitors. Look for visible signs of leak or of busted capacitors. Look for bulged capacitors or damaged components- burnt or busted. Use a multimeter to check the continuity or shorting in components, if so detach from circuit and test . If the voltage builds up and the set power ON and then shuts up then the suspected section must be checked in detail.

The processor must have the +5 voltage to the function properly , the +B and secondary voltages also must be checked to infer the fault. Trace with caution and in running through the signal path , circuit trail.

If the set power on when it is tapped then it is typical with aging as many sets develop dry soldering joints over a period of heating and cooling.So my advice is to check the set for some loose joints that have played on to give you these erratic shut downs or poor performance.

The best way to check for loose connections is to tap lightly when the set is powered on , If there is change while tapping then it seems that there are DRY solder joints. Remove main plug, the covers - with caution of high voltage, check for dry joints, use a good soldering iron to solder all suspected points.

Sometimes the fault occurs when the set warms up, if so you can simulate the heat using a hair dryer on the suspected areas, try with the power supply, distribution, Processor controller, driver controllers on the A/V related sections. Also the use a FREEZE-IT spray can simulate the components to cool and show up the fault.

Based on the above method you must be able to locate the area of fault and solder the sections. Sometimes large IC's- ones with more pins- tend to have drying in some pins and so cause faults related to the IC's protocol. Have a rough idea of looking into the areas to reduce the time of probing.