Long story short... ccfl's failed, bought this "ca-155" led replacement but can't identify pin/wire assignment on both power supply board and logic board since neither have anything printed over the pcb, no ENA, DIM, VCC, GND, 5v, BL-ADJ or anything like that, nothing!!!
Hello everyone and let me start with two warnings to help you understand the text wall ahead :p
first, my english is absolutely bad, mediocre at best so i apologize in advance for making your eyes bleed, you may think "then what are you doing here and not searching the help you need in some spanish forum?" well i've tried, seriously but people tells me either to "git gud", leave the task to professionals and stop wasting everyone else's time or they cant help at all.
Finally, im a total newbie with electronics, literally i have no clue about all this stuff, the most i've done was repairing my old Logitech surround speakers, two smartphone power adapters, LED garden lamps, xbox 360 controller (the tiny rumble motors) and replacing capacitors on two old pc motherboards, that's pretty much it.
I know how to solder tiny wires and tiny pcb boards (the work i did on the logitech speakers, very tedious but was a success) i have 3 soldering irons, tips, desoldering braid, flux, alcohol and more stuff, also a cheap chinese digital multimeter, alligator clips yada yada... BUT knowing what's going on over this labyrinth of PCB paths with so many resistors and other unknown stuff is something entirely different... totally out of my league.
I went already to 3 technicians and all of them told me there's no fix or its so tedious, complicated that buying a new monitor is the best course of action, also none of them knew about this "ca-155" kind of board to replace ccfl's i told them about this kind of solution but they just looked at me like "uhh what are you talking about? what's that? uhhh?"
So back to the story with more details, CCFL's failed in my 11 years old Benq G2024HD monitor, one lamp had this carbonized/blackened shade at one end, then there was this flickering and a pink shade on half of the screen, i've read about it and it was the ccfl, technicians told me ccfl was the problem indeed and best option was to purchase a new monitor because ccfl's replacements can be found nowhere or the price was so ridiculous high that getting a new monitor was the best choice to save time and money... welp i didn't listen and here we are...
i bought this thing called CA-155 some sort of "universal LED driver" to replace ccfl's, here's the manufacturer website:
http://www.creatall.com/en/product/C...converter.html
My package arrived with 2 LED strips and some wires, many people on ebay, amazon and more sell this "combo" for ccfl's replacement, i watched some youtube tutorials about the installation and it seemed to be simple, piece of cake right? nope... Neither the power supply board or the logic board have the pin/wire identification printed on the PCB, there's nothing, only the CN701 and some other weird codes for resistors, capacitors, diodes and stuff like that.
WARNING... disgusting pics ahead... the wooden bench where i do most of my work (electronics, painting, assembly, cutting and more) is so disgusting, not only that but 11 years of getting dust, heat and the nasty habit of smoking made all the wires, pcb and stuff get a brownish ugly color in different areas, that's repulsive i know, apologies...
First pic showing the two boards.
https://imgur.com/8wUKHUy
CN701 stands for the 12 pin white connector (i guess, not sure rly) and each board has just 6 cables connected to this 12pin connector.
https://imgur.com/j39TFJT
here's the whole album:
https://imgur.com/a/x53LAqX
A black, Brown, a Red (almost brownish-red wire), orange, yellow and finally the green wire, so without anything printed on the pcb there's no way i could find what they do unless i find info on the internet, well that's what i did yesterday without luck...
The Benq G2024HD monitor service manual doesn't have any schematic page showing each wire purpose, here's the manual:
https://www.manualslib.com/manual/93...hd.html#manual
Page 60 starts showing the schematics, maybe i'm missing something since im a newbie but just in case maybe this could help you guys.
Anyway i spent hours searching every google result for this monitor and couldn't find anything, all the other service manuals for different Benq monitors show schematics with the pin/wire assignment most of them are boards with 6,8 or 10 pin connectors iirc i couldn't find any other model with the 12pin connector
Youtube didn't work either so i googled the power supply model and it was the same, nothing useful just tons of chinese websites selling the board and ebay, aliexpress, amazon results selling 2nd hand boards.
I did find another pdf file with schematics tho, but not for my power supply, its for the 4H.0BH02.A00 with 11 pin connector and the one i have is the 4H.0NC02.A01
https://cdn.badcaps-static.com/pdfs/...6edd84ecfd.pdf
Seriously, i couldn't find schematics for the whole monitor or power supply and trying to find anything for the logic board was even worse, cero!! nada!!! and looking for information about wires color code makes you get even more confused because depending on the country and device (audio, cars, computers and more) the meaning changes so i wouldn't risk damaging (and wasting more time) playing with the soldering iron and randomly solder wires with some sort of "trial and error" method till LED's turned on.
The only option i have is asking for some advice and help from you guys, and of course, learning how to properly use a Multimeter because that's the last resort, measuring each wire till i get X values and then find out the meaning of each result.
But i'm a chicken, i saw videos where you have to plug the monitor and give it some current before measuring with the multimeter probes because doing it without current won't give ya exact values or nothing at all... right? idk... I am afraid of getting some shock or burning the whole board lol
In those videos people plug the monitor to the current, then they start the "ON" signal by just hitting the "ON" button on the monitor control board or use some "jumper" to start it.
So with the monitor having current they put the black probe on any screw hole or in any place of the metal chassis and then with the red probe they measure each wire, depending on the board they get 5v, 3,3v sometimes 20v or more and then 0v for some wires (direct current mode on multimeter) that's how they identify the purpose of each cable.
OMG im clueless so im gonna finish this with some questions:
1- To test/measure each cable from the logic and/or power supply board with my cheap chinese multimeter... Do i have to start/give electric current/power to the boards?
2- what's the most basic and critical safety measures before doing it? i know i shouldn't drop any metal stuff over the solder joints or short capacitors touching both legs at the same time, is there anything else? like not touching at all the big 450v capacitor or any particular component due risk of shock and stuff like that? also i wouldn't use the multimeter probes to randomly check stuff i don't know having the current flowing through the whole system.
3- Ground is any metal piece? like the metal chassis (even if its not attached to the power/logic board?) screw holes with nothing around or some big joint with nothing around?
Anyway, as you guys already noticed, i should hand this to professionals instead "trying to fix it on my own" but once again, they cant/want to fix it, the lcd screen is fine, both the power and logic board are fine, all is cool but CCFL's made this piece of hardware useless, i could just buy a new modern LED monitor with no problems but I HATE when something that isn't totally broken goes to the trash just like that, when everything else is OK and just one component fails then buy new one? that sucks...
I WILL get a new gaming monitor soon but my sister could use this one when fixed, she has this tiny 17" or something Hewlett packard LED monitor so thats another reason for my stubbornness .
Finally (yes i promise this is the end) if this forum is not intended for newbies or advicing/teaching people with no experience then i would understand if gets locked, removed or anything like that, been there done that, i just had to give it a shot, sorry for the typos, spelling and the engrish have a nice day!!!
Hello everyone and let me start with two warnings to help you understand the text wall ahead :p
first, my english is absolutely bad, mediocre at best so i apologize in advance for making your eyes bleed, you may think "then what are you doing here and not searching the help you need in some spanish forum?" well i've tried, seriously but people tells me either to "git gud", leave the task to professionals and stop wasting everyone else's time or they cant help at all.
Finally, im a total newbie with electronics, literally i have no clue about all this stuff, the most i've done was repairing my old Logitech surround speakers, two smartphone power adapters, LED garden lamps, xbox 360 controller (the tiny rumble motors) and replacing capacitors on two old pc motherboards, that's pretty much it.
I know how to solder tiny wires and tiny pcb boards (the work i did on the logitech speakers, very tedious but was a success) i have 3 soldering irons, tips, desoldering braid, flux, alcohol and more stuff, also a cheap chinese digital multimeter, alligator clips yada yada... BUT knowing what's going on over this labyrinth of PCB paths with so many resistors and other unknown stuff is something entirely different... totally out of my league.
I went already to 3 technicians and all of them told me there's no fix or its so tedious, complicated that buying a new monitor is the best course of action, also none of them knew about this "ca-155" kind of board to replace ccfl's i told them about this kind of solution but they just looked at me like "uhh what are you talking about? what's that? uhhh?"
So back to the story with more details, CCFL's failed in my 11 years old Benq G2024HD monitor, one lamp had this carbonized/blackened shade at one end, then there was this flickering and a pink shade on half of the screen, i've read about it and it was the ccfl, technicians told me ccfl was the problem indeed and best option was to purchase a new monitor because ccfl's replacements can be found nowhere or the price was so ridiculous high that getting a new monitor was the best choice to save time and money... welp i didn't listen and here we are...
i bought this thing called CA-155 some sort of "universal LED driver" to replace ccfl's, here's the manufacturer website:
http://www.creatall.com/en/product/C...converter.html
My package arrived with 2 LED strips and some wires, many people on ebay, amazon and more sell this "combo" for ccfl's replacement, i watched some youtube tutorials about the installation and it seemed to be simple, piece of cake right? nope... Neither the power supply board or the logic board have the pin/wire identification printed on the PCB, there's nothing, only the CN701 and some other weird codes for resistors, capacitors, diodes and stuff like that.
WARNING... disgusting pics ahead... the wooden bench where i do most of my work (electronics, painting, assembly, cutting and more) is so disgusting, not only that but 11 years of getting dust, heat and the nasty habit of smoking made all the wires, pcb and stuff get a brownish ugly color in different areas, that's repulsive i know, apologies...
First pic showing the two boards.
https://imgur.com/8wUKHUy
CN701 stands for the 12 pin white connector (i guess, not sure rly) and each board has just 6 cables connected to this 12pin connector.
https://imgur.com/j39TFJT
here's the whole album:
https://imgur.com/a/x53LAqX
A black, Brown, a Red (almost brownish-red wire), orange, yellow and finally the green wire, so without anything printed on the pcb there's no way i could find what they do unless i find info on the internet, well that's what i did yesterday without luck...
The Benq G2024HD monitor service manual doesn't have any schematic page showing each wire purpose, here's the manual:
https://www.manualslib.com/manual/93...hd.html#manual
Page 60 starts showing the schematics, maybe i'm missing something since im a newbie but just in case maybe this could help you guys.
Anyway i spent hours searching every google result for this monitor and couldn't find anything, all the other service manuals for different Benq monitors show schematics with the pin/wire assignment most of them are boards with 6,8 or 10 pin connectors iirc i couldn't find any other model with the 12pin connector
Youtube didn't work either so i googled the power supply model and it was the same, nothing useful just tons of chinese websites selling the board and ebay, aliexpress, amazon results selling 2nd hand boards.
I did find another pdf file with schematics tho, but not for my power supply, its for the 4H.0BH02.A00 with 11 pin connector and the one i have is the 4H.0NC02.A01
https://cdn.badcaps-static.com/pdfs/...6edd84ecfd.pdf
Seriously, i couldn't find schematics for the whole monitor or power supply and trying to find anything for the logic board was even worse, cero!! nada!!! and looking for information about wires color code makes you get even more confused because depending on the country and device (audio, cars, computers and more) the meaning changes so i wouldn't risk damaging (and wasting more time) playing with the soldering iron and randomly solder wires with some sort of "trial and error" method till LED's turned on.
The only option i have is asking for some advice and help from you guys, and of course, learning how to properly use a Multimeter because that's the last resort, measuring each wire till i get X values and then find out the meaning of each result.
But i'm a chicken, i saw videos where you have to plug the monitor and give it some current before measuring with the multimeter probes because doing it without current won't give ya exact values or nothing at all... right? idk... I am afraid of getting some shock or burning the whole board lol
In those videos people plug the monitor to the current, then they start the "ON" signal by just hitting the "ON" button on the monitor control board or use some "jumper" to start it.
So with the monitor having current they put the black probe on any screw hole or in any place of the metal chassis and then with the red probe they measure each wire, depending on the board they get 5v, 3,3v sometimes 20v or more and then 0v for some wires (direct current mode on multimeter) that's how they identify the purpose of each cable.
OMG im clueless so im gonna finish this with some questions:
1- To test/measure each cable from the logic and/or power supply board with my cheap chinese multimeter... Do i have to start/give electric current/power to the boards?
2- what's the most basic and critical safety measures before doing it? i know i shouldn't drop any metal stuff over the solder joints or short capacitors touching both legs at the same time, is there anything else? like not touching at all the big 450v capacitor or any particular component due risk of shock and stuff like that? also i wouldn't use the multimeter probes to randomly check stuff i don't know having the current flowing through the whole system.
3- Ground is any metal piece? like the metal chassis (even if its not attached to the power/logic board?) screw holes with nothing around or some big joint with nothing around?
Anyway, as you guys already noticed, i should hand this to professionals instead "trying to fix it on my own" but once again, they cant/want to fix it, the lcd screen is fine, both the power and logic board are fine, all is cool but CCFL's made this piece of hardware useless, i could just buy a new modern LED monitor with no problems but I HATE when something that isn't totally broken goes to the trash just like that, when everything else is OK and just one component fails then buy new one? that sucks...
I WILL get a new gaming monitor soon but my sister could use this one when fixed, she has this tiny 17" or something Hewlett packard LED monitor so thats another reason for my stubbornness .
Finally (yes i promise this is the end) if this forum is not intended for newbies or advicing/teaching people with no experience then i would understand if gets locked, removed or anything like that, been there done that, i just had to give it a shot, sorry for the typos, spelling and the engrish have a nice day!!!
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