This model is using the famous TL1451ACN Pulse width modulation (PWM) IC-some preferred to call it as inverter IC. Pin 9 is the VCC supply input and it should have about 12 Volts when the strength is “on”. Measuring the pin with my faithful digital multimeter, it says only about 3 v signifies there’s a problem in the supply range. It could be components that are faulty that dragged down the road or it could be the switch mode power supply itself that don’t produce enough power.
In order to find the answer as which section is providing problem, the first hint was that the strength LED indicator lit and also this show that the IC is supplying enough power to the circuit. Another hint is that the meter is registering about 16 v at the input of the 2A fuse. Because of these clear responses, we can conclude that the switch mode strength supply is working fine. You can also use a 12 volt light bulb to confirm it. You may read my other post on samsung tv repair merstham articles which talks about using 12 volt bulb for troubleshooting purposes.
I kept on requesting myself, why the volts drop to 3 volts after the fuse. Ahead of the fuse it reads about 16 volt but after the merge it reads only 3 volts! I didn’t believe the fuse, because the fuse can only either yes or no and no between. The first circuit that I checked out was the start circuit but all components checked to be okay. We even desoldered the flag 9 of TL1451ACN inverter IC just to ensure it is not this IC that pulled down the volts.
This problem really difficulties my troubleshooting and restoring skill, because almost all suspected components already checked to be working. Actually the start circuit transistors (C945 & A733) We direct replaced, afraid they would breakdown when under load. The only component that I didn’t check was the fuse! By using my meter put across the fuse, rather than getting low ohms or zero ohm reading I got one. 012 Kilo ohms! We have got a surprised and don’t believe a blend can actually go into high ohms rather than open up circuit. I usually thought that a fuse will either be close up or open circuit. The fuse with zero ohms turned into high ohm thus the 16 volts dropped to 3 v! I’ve came across plenty of this kind of merge but this is the very first time a fuse changed into high resistance.
Exchanging the fuse only put the DELL E152Fpb FLATSCREEN Monitor back to life. The lesson learned from here is the fact that don’t assume that a component is always in a good working condition. You have to confirm it with your meter of course, if you still suspect the component is giving problem, simply replace it with a known good one and retest the equipment. Semiconductors can breakdown when under full operating voltage.
I have a lot of friends that contain LCD monitors (I prefer CRT still) and the majority of them are going on about stuck pixels and how they can repair a LCD monitor that has this sort of problem. We will show you 3 simple ways that you can use to remove this problem without having to go to someone else and maybe pay that respective person. Stuck -pixels usually appear because the liquid inside the LCD monitor is not propagate properly, therefore 1 or more pixels may continue to be stuck with one color or maybe stay black, this will depend. But now lets get down to the explaining part.