Power board main

I rather suspect IC1 TDA7293 is the cause of your problem. If this is the case you will need to check the speaker/s

Replace the parts with the original ones, a .5 ohm difference on a resistor on the video circuits will cause the unit not to work correctly.

If TV is completely dead you have either a bad power or a bad main board.

Talking form experience I'd go with the power board first.

The alternative is to make sure the power board outputs the normal standby power to the main board and see that the main is not responding to command. That would point to the main.

The fact that Q406 is not shorted does not mean it is good let alone that the power board is good; while the most common issue there it is definitely not the only one that can happen.

You can send in the board for inspection/repair if interested although you're probably better off just buying a replacement.

check for a power supply failure, could be a defective component like regulator and transistor. you could also look at the main board if their is a burnt parts which circuit doesn't circulates.

if their is no any power indicator that light in the front panel, it was a power supply board failure. you must look first the fuse if busted, then before you replace it ensure no other part has damaged like shorted diode, transistor, transformer and regulator.

Pleasant day!

The problem could be the power supply or the main board.all you have to do is to follow this simple and easy way of troubleshooting.

1. Remove the cover.
2. Plug-in your DVD player and power it ON to perform a voltage data/check.
3. Check the input power of the DVD.Use multimeter tester to test the AC voltage (AC range).It should have 120v or 240vac depends on the requirement of your DVD or the main supply that comes on the outlet.If no voltage reading,your power cord have a continuity problem.Replace it with the same type and A.W.G number standard.
4. If the power cord got voltage reading.Next is test the output voltage of power supply such as 5vdc for the main board and logic supply using multimeter (DC range).If no voltage reading,the problem could be the power supply board.

Check the following parts which commonly breaks on power supply board.

• The power transistors (regulators)-It is commonly binds on heat sink and found on the primary of the chopper.use a multimeter (range diode test) to check if it is shorted.
  
• The fuse-able resistors-it is the resistor that have low resistance such as 1ohm 2.2 ohms etc.It is usually found near the power regulators/transistors.Use multimeter (range resistance) to check if it is open or change value.
  
• The capacitors-it is the one who can store voltage.If you have capacitance meter you can test that,if none just look at the appearance of the capacitor if it is bulge on top or leak.

NOTE: If you found the defective parts that mention above,replace it with the same type and ratings.
When the problem is still there,The problem of the power supply is major and not for D.I.Y.I suggest to send it to the qualified technician or just buy a new one.

5. If the power supply have output voltage.The problem could be the main board and unfortunately the main board is not for D.I.Y because composition of the board is very sensitive.The only way to fix it is to buy a new main board unit.

I hope this solution could fix your problem.Please response if you have any comment and question.Thank you and good luck.

The cheapest option is to replace the transistors (a quick check on google will tell you how much they are). If they are common transistors you will be able to find them and get them quicker then searching for a board that could be no longer being made.

The fuse blows all time on High Voltage Poewr Supply, on HP Color Laserjet 5550dn,

LCD TV TroubleshootingThe defective LCD TV may have the following common symptoms:

Symptom: No picture on screen but LCD TV still has sound.
Solutions: The problem is cause by defective inverter. Replacing ivnerter will solve hte problem. Symptom: Screen flash on and off between 1/2 to a few seconds, but power indicate light stays on and TV still has sound.
Solutions: The problem is cause by defective inverter. Symptom: Blue Screen but no picture
Solutions: The problem is cause by defective Main Board(AD Board). In some cases, this problem may cause by the defective Screen Controller board. Thsi board is mounting on teh back of LCD TV Scree. Symptom: Power light stays on but no display and sound
Solutions: The problem is cause by defective Main Board(AD Board) or Power supply board. Symptom: No Power or Power indicate light does not lits
Solutions: The problem could cause either by defective Power supply board or defective Main Board(AD Board). Symptom: Screen is half dim and half bright
Solutions: The problem is cause by defective LCD Panel.It needs to be replace.

This is a power supply problem. Try to check the fuses ,fusable resistor ,capacitor and transistor in power supply board.

Hope it may help you;

Regards,
VOTIT

Easy fix!!!!!!! CUT JUMPER 300 on main board _ [FACTORY DEFECT] protection jumper
If you have a warranty take TV back to store if not easy fix.