Samsung LCD TV Repair - TV Wont Turn On - How to Replace Power Supply & Main Board
- il y a 6 ans
Samsung TV Repair How to troubleshoot standby problem \r
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This video is designed to be a guide for testing and troubleshooting your TV repair. Please note that other complications may exist that arent addressed in this guide. While we always strive to provide accurate and detailed information, we cant guarantee that it will fix your TVs issues. \r
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So in this video today we are going to be looking at a Samsung LCD and how to diagnose if you have a bad main or a bad power supply. This particular power supply is the BN44-00197A and this is a high voltage power supply. So it has these two high voltage leads that go out to the inverters and it has a couple of connections that go to the main board. If your power supply looks different, we are going to take a look at how to check those power supplys too, but it will be a little bit different from this one. \r
So this video is for if you have no standby, or if you have standby and the TV will not power on and also if you have no backlights. It kind of covers a lot with this one. So in order to find out where the problem lies, we are going to go ahead and disconnect the main board by undoing the two cables from the power supply. We are then going to use some jumpers to force the power supply and the backlights to turn on and then we will know that if the backlights come on and the voltages are all present that the power supply is good. \r
Now in this case, I have just got some jumper wire and you can also use resistors, sometimes it is a little bit safer to put a resistor in there, but straight wire will work too. \r
You can see here we have got a little diagram showing the pinouts for the connector. You can see that pin 1 is going to be the power on off and down to pin 3 is our 5 volt standby and those are the two pins that we have to jumper. On these connectors, because they are double row pins they mark pin 1 that little triangle right there and on these it goes pin 1, pin 2, 3, 4, and it goes back and forth. So we know that pin 1 is going to the first pin and pin 3 is going to be the next pin over from it. \r
Go ahead and follow that brown wire down and thats going to be on this side and we can take our jumper wire and put it into the first hole and the one right next to it, pins 1 and 3. The nice thing is that if you have the insulated wire, you dont really care if it falls over and where it lands because it wont short out. If you have bare wire, be careful that it does not touch the metal chassis, because otherwise it could short out which could be bad. \r
On the second connector you see its got the 5 volt detect line and inverter on off, thats pins 1 and 5. Then its going to be the 2 outside pins. Jumper it like so and then again we have insulated cable so we dont care about where it lands. Now we can go ahead and plug in power and see what happens. So if your backlights are working correctly, you are going to see the white lights shining through the holes in the back of the TV. This light should turn on pretty much immediately, there shouldnt be any real delay. As soon as you apply power, you should see this white light shining through. If you see that, that means your backlights are good. With those jumpers in, it should stay on permanently. If you had problems with your backlights failing after a few minutes you could put the jumpers in and run it and then see if the light stays on. If it does, then you know that the power and backlight inverters are good and that you ually have a main board issue. \r
This is also a good chance to take your meter and just check that the other voltages on the power supply are correct and present. So I have got it set to DC and we will just use the chassis for a ground, usually I just find an empty screw hole and drop the negative probe in there. Now we can go through and we can probe the connections. This is standby, which we know we have, theres the terminal voltage and we can go down here and check for our voltages. So we have got a 12.4 volts which is close enough. It should be 13, but half a volt is pretty normal. You can just go through and compare and make sure that they are all present and correct. If they are all good, then you know for sure you have got a main board issue and you can go ahead and replace the main. \r
\r
TV Repair Made Easy™\r
© new ShopJimmy.com, LLC.
Click Here for LCD TV REPAIR PARTS: \r
\r
\r
Click Here to Buy an ESD Wristband! \r
\r
This video is designed to be a guide for testing and troubleshooting your TV repair. Please note that other complications may exist that arent addressed in this guide. While we always strive to provide accurate and detailed information, we cant guarantee that it will fix your TVs issues. \r
\r
So in this video today we are going to be looking at a Samsung LCD and how to diagnose if you have a bad main or a bad power supply. This particular power supply is the BN44-00197A and this is a high voltage power supply. So it has these two high voltage leads that go out to the inverters and it has a couple of connections that go to the main board. If your power supply looks different, we are going to take a look at how to check those power supplys too, but it will be a little bit different from this one. \r
So this video is for if you have no standby, or if you have standby and the TV will not power on and also if you have no backlights. It kind of covers a lot with this one. So in order to find out where the problem lies, we are going to go ahead and disconnect the main board by undoing the two cables from the power supply. We are then going to use some jumpers to force the power supply and the backlights to turn on and then we will know that if the backlights come on and the voltages are all present that the power supply is good. \r
Now in this case, I have just got some jumper wire and you can also use resistors, sometimes it is a little bit safer to put a resistor in there, but straight wire will work too. \r
You can see here we have got a little diagram showing the pinouts for the connector. You can see that pin 1 is going to be the power on off and down to pin 3 is our 5 volt standby and those are the two pins that we have to jumper. On these connectors, because they are double row pins they mark pin 1 that little triangle right there and on these it goes pin 1, pin 2, 3, 4, and it goes back and forth. So we know that pin 1 is going to the first pin and pin 3 is going to be the next pin over from it. \r
Go ahead and follow that brown wire down and thats going to be on this side and we can take our jumper wire and put it into the first hole and the one right next to it, pins 1 and 3. The nice thing is that if you have the insulated wire, you dont really care if it falls over and where it lands because it wont short out. If you have bare wire, be careful that it does not touch the metal chassis, because otherwise it could short out which could be bad. \r
On the second connector you see its got the 5 volt detect line and inverter on off, thats pins 1 and 5. Then its going to be the 2 outside pins. Jumper it like so and then again we have insulated cable so we dont care about where it lands. Now we can go ahead and plug in power and see what happens. So if your backlights are working correctly, you are going to see the white lights shining through the holes in the back of the TV. This light should turn on pretty much immediately, there shouldnt be any real delay. As soon as you apply power, you should see this white light shining through. If you see that, that means your backlights are good. With those jumpers in, it should stay on permanently. If you had problems with your backlights failing after a few minutes you could put the jumpers in and run it and then see if the light stays on. If it does, then you know that the power and backlight inverters are good and that you ually have a main board issue. \r
This is also a good chance to take your meter and just check that the other voltages on the power supply are correct and present. So I have got it set to DC and we will just use the chassis for a ground, usually I just find an empty screw hole and drop the negative probe in there. Now we can go through and we can probe the connections. This is standby, which we know we have, theres the terminal voltage and we can go down here and check for our voltages. So we have got a 12.4 volts which is close enough. It should be 13, but half a volt is pretty normal. You can just go through and compare and make sure that they are all present and correct. If they are all good, then you know for sure you have got a main board issue and you can go ahead and replace the main. \r
\r
TV Repair Made Easy™\r
© new ShopJimmy.com, LLC.