My samsung ln46a650a1fxza lcd warms up and then it goes off with no chime and comes back on with a chime but the picture is pixalized somewhat. So far I changed the caps on the power board,but still get the off and on. I let it cool down and started it again and while it was on I used a IR laser thermometer to look for hot spots on the power board and the main board . the power board was only around 99 deg. but the main board had a couple really hot spots. 180 deg. so I used a hair drier on the hot spots after it cooled down got it hot to 205 deg and it shut off with no chime and then came back on. I have a pic of a component that I heated up but I don't know what it is.
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Samsung LN46A650A1FXZA
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Re: Samsung LN46A650A1FXZA
Its an inductor, could be high resistance causing it to overheat and go open. You should be able to temporarily pull it and solder in a bypass and see if your problem goes away. Im sure more experienced voices will chime in shortly.Liberating magic smoke one part at a time
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Re: Samsung LN46A650A1FXZA
That is the inductor for buck switching power supply, do not bypass it or or you will cause more damages, there is MOSFET next to it that is part of the switching circuit, if that MOSFET is shorted instead of switching on and off at high frquency, it will cause lots of current flowing through that inductor. There is an IC for driving the Gate of that MOSFET, the Gate drive may stuck high due to bad IC. You can also have shorted load.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Samsung LN46A650A1FXZA
The resistance of that inductor will be really low, you will need to find the diagram of this TV to really do in depth troubleshooting to component level.
Did you look at elektrotanya.com to see if it has the service manual for this TV?Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Samsung LN46A650A1FXZA
Samsung don't let it manuals float around on line,but I will check your site and do some more poking around on line and at the city library. In the mean time I put a small fan over the inducer to pull away excess heat . Its from a Sony xbr5 now I have a frankenlcdtv.lol . Seems to be working so far but I have the ac on now. Thanks for the lead for a manual.
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Re: Samsung LN46A650A1FXZA
On the right of this board where does the flat flex connector go?
https://www.badcaps.net/forum/attach...0&d=1373783549
I do not remember that on both of my LE40A656's I have fixed, which are very similar models.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: Samsung LN46A650A1FXZA
Took the questioned inductor off.Took a ohms reading and I get 0.0 The fet is not shorted there is a small diode to the left even with bottom of inductor. That is very hot also 185+ deg.I'm going to solder one end off and get a reading today. if it is sending current both ways will that make the inductor hot. Where is the ic that tells the fet to open and close. Thanks so far for the help ,you guys are keeping a lot of e-waste out of land fills,and I am learning a bucket full of info.
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Re: Samsung LN46A650A1FXZA
An inductor in a buck converter will have current flowing one direction in most cases, but I couldn't think of a fault that would cause it to have current flow the other way... or even what that would cause. Personally, I'd be focusing more on that large heatsinked processor.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: Samsung LN46A650A1FXZA
I will get a picture of the whole chassis today . I will have to take the back off again. When I change something, I always put it all back together, so not to change any other conditions of when the problem started. I know that may be a bit much of me, but I like to do things right the first time.
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Re: Samsung LN46A650A1FXZA
I've never had issues with working with the cover off after 50+ TVs. There should be no problem in doing so.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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Re: Samsung LN46A650A1FXZA
1.2V sounds right for that kind of processor, you need to see what it measures when not working.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.
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