HP F1723 LCD Monitor- How To Repair No Power
This HP1723 17" LCD Monitor came in with the criticism of no power. Upon further inspection I could hear a mushy intermittent sound coming from the both front speakers. Because the audio system can produce some sound, this means that the facility supply must be working positive and it might be some bad parts situated at the secondary facet that had prompted the facility supply voltage to drop to not start. The ability LED would not gentle as a result of the sign was coming from the Microcontroller (MCU) IC. Which means that if the MCU didn't obtain the proper voltage from the power supply, it is not going to ship output voltage to the power LED.
As normal, to open LCD Monitor cover , one need to be careful of not scratching or leaving a mark on the plastic casing otherwise the shopper could not wish to accept his or her broken or badly scratch LCD Monitor. Once the cover have been eliminated, you need to remove another 4 screws (two at either side) in an effort to take out the power/inverter and the Main board. For some LCD Displays, the second you may have open the quilt, you could possibly simply take away all the boards.
The power provide and the inverter circuit are in one board whereas the Main board and the audio board are in separate board. As talked about before in my previous articles, I do not immediately start to troubleshoot and restore any board until I've scanned all the elements with my eyes first. The power provide/inverter board look very new and the obvious signal that I may see was two filter capacitors (1000uf 16 Volt) had a slight bulge on prime of its casing. I believe these bulged electrolytic capacitors that had prompted the facility provide not to perform properly. I've checked all other e-caps too however all discovered to be good.
Normally at any time when a filter capacitor located on the secondary side of switch mode power supply (SMPS) have a too excessive ESR value, the voltage will drop greater than half causing many circuits will not work. Since I already found the dangerous e-caps, I've to make sure that the secondary diodes (this LCD Monitor is using Schottky diodes) do not go defective or leaky too. Upon checking the Schottky diodes (half quantity are SRF20100C and SP10150) I discovered each of them to be working fine. Changing solely the two dangerous e-caps with a good one solved the LCD Monitor problem.
Now get this, if you want to be good in any digital gear restore, if potential analyze different circuits too. That means when you every time substitute only the fuse and the bridge rectifier you will not study something past that downside and you're going to get bored easily. Let's take my case for instance, after the replacement of the capacitors I'll often analyze different circuits too like finding out what kind of part numbers certain components are using, which type of the inverter circuit is belong to i.e. Buck Royer or direct drive?, why each backlight circuit are utilizing 4 ballast capacitors?, What number of backlights the LCD Monitor is using, what is the inverter IC half number, what is the supply voltage to the inverter IC? What number of LED bar lighted up when check on the secondary winding of the high voltage transformer? What would happen if I pull out one of many backlight (will it nonetheless work or shut down?). What's the brightness line voltage if set to minimum and most? It's a must to answer all of those questions if you wish to be good at LCD Monitor repair. You can apply this type of questions on other digital gear too. This is a steady means of learning learn how to be good in electronic repair.
I do not need you to exchange caps or fuse everyday without realizing how other circuits perform or what are the elements used in different circuits. Though to analyze different circuits take you plenty of time however I can guarantee you that the time you have got spent are value it. You will not be capable to go far when you've got set your pondering by simply altering parts and never knowing the surrounding. If you wish to improve in digital repair then you definitely need a change of mindset in you and only you yourself can make the totally different! Try this method and I consider troubleshooting digital or LCD Monitor repair will never be the identical again. Have an important and a fantastic 12 months!
HP F1723 LCD Monitor- How To Repair No Power
This HP1723 17" LCD Monitor came in with the criticism of no power. Upon further inspection I could hear a mushy intermittent sound coming from the both front speakers. Because the audio system can produce some sound, this means that the facility supply must be working positive and it might be some bad parts situated at the secondary facet that had prompted the facility supply voltage to drop to not start. The ability LED would not gentle as a result of the sign was coming from the Microcontroller (MCU) IC. Which means that if the MCU didn't obtain the proper voltage from the power supply, it is not going to ship output voltage to the power LED.
As normal, to open LCD Monitor cover , one need to be careful of not scratching or leaving a mark on the plastic casing otherwise the shopper could not wish to accept his or her broken or badly scratch LCD Monitor. Once the cover have been eliminated, you need to remove another 4 screws (two at either side) in an effort to take out the power/inverter and the Main board. For some LCD Displays, the second you may have open the quilt, you could possibly simply take away all the boards.
The power provide and the inverter circuit are in one board whereas the Main board and the audio board are in separate board. As talked about before in my previous articles, I do not immediately start to troubleshoot and restore any board until I've scanned all the elements with my eyes first. The power provide/inverter board look very new and the obvious signal that I may see was two filter capacitors (1000uf 16 Volt) had a slight bulge on prime of its casing. I believe these bulged electrolytic capacitors that had prompted the facility provide not to perform properly. I've checked all other e-caps too however all discovered to be good.
Normally at any time when a filter capacitor located on the secondary side of switch mode power supply (SMPS) have a too excessive ESR value, the voltage will drop greater than half causing many circuits will not work. Since I already found the dangerous e-caps, I've to make sure that the secondary diodes (this LCD Monitor is using Schottky diodes) do not go defective or leaky too. Upon checking the Schottky diodes (half quantity are SRF20100C and SP10150) I discovered each of them to be working fine. Changing solely the two dangerous e-caps with a good one solved the LCD Monitor problem.
Now get this, if you want to be good in any digital gear restore, if potential analyze different circuits too. That means when you every time substitute only the fuse and the bridge rectifier you will not study something past that downside and you're going to get bored easily. Let's take my case for instance, after the replacement of the capacitors I'll often analyze different circuits too like finding out what kind of part numbers certain components are using, which type of the inverter circuit is belong to i.e. Buck Royer or direct drive?, why each backlight circuit are utilizing 4 ballast capacitors?, What number of backlights the LCD Monitor is using, what is the inverter IC half number, what is the supply voltage to the inverter IC? What number of LED bar lighted up when check on the secondary winding of the high voltage transformer? What would happen if I pull out one of many backlight (will it nonetheless work or shut down?). What's the brightness line voltage if set to minimum and most? It's a must to answer all of those questions if you wish to be good at LCD Monitor repair. You can apply this type of questions on other digital gear too. This is a steady means of learning learn how to be good in electronic repair.
I do not need you to exchange caps or fuse everyday without realizing how other circuits perform or what are the elements used in different circuits. Though to analyze different circuits take you plenty of time however I can guarantee you that the time you have got spent are value it. You will not be capable to go far when you've got set your pondering by simply altering parts and never knowing the surrounding. If you wish to improve in digital repair then you definitely need a change of mindset in you and only you yourself can make the totally different! Try this method and I consider troubleshooting digital or LCD Monitor repair will never be the identical again. Have an important and a fantastic 12 months!
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