[SOLVED] Help with setting up LG Flatron L1932P-SF monitor power button

Apr 9, 2021
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Greeting everyone, firstly I want to apologize if the thread already exist or the place is not the correct one, however I already made detailed search and wasn't able to find anything of use for my case.
I have and old LG Flatron L1932P-SF, which I still use and one beautiful day the power button of the monitor stopped working, that being said, I couldn't turn it on. I disassembled it very carefully, removed the power button took another one (the menu button) and soldier it on the place of the power button and vise versa. I assembled everything and hooked up the monitor, the "new" power button worked beutifully, however then the menu option started popping up for no reason in the middle of the screen, As this was very painful to work with, I disconnected the whole PCB with all the buttons and now the monitor is working fine (no menu pop-ups), however there is no power button neither. Since this PCB with all the buttons (power button included) is hooked up seperatly by 7/8 wires (I will give much more details if needed) is there a way to make a simple power switch using those wires (without using the whole PCB)?
Thank you in advance! :)
 
Solution
Is one of the PCB buttons marked in some manner that can be identified as "Power" or "On/Off" , etc..?

Each button appears to have some labeling. However, I could not get any Zoom to get a good look at the PCB image.

I counted 7 buttons on the PCB board but only 6 wires leading away from the PCB board.

The key, for you, is to trace all of the wires about using the monitor's service manual and the on-site advantage of determining (eventually) what wires go where and through what components - especially the power button.

Use part numbers, diagram references, etc. per Manual Page 19 & 20. Much easier to map with the entire physical monitor sitting in front of you.

As for breadboarding that is a topic easily googled and you can...

Ralston18

Titan
Moderator
Likely an inline switch inserted into one of those 7 or 8 wires would be all that is needed.

Which wire (s) and what type of switch - no idea.

Are you using a breadboard? If so then you could easily test if one particular wire serves the power on/off function.

You might be able to trace along the PCB and wires to identify where the power button could be inserted.

However inserting a switch anywhere is a bit risky without fully knowing what each wire is for - a schematic is needed.

I did a bit of googling looking for applicable schematics, service manuals etc..

Found some links offering "manuals" but many looked very sketchy so did not click.

Did click one site that appeared hopeful but immediately got AV warnings etc.. Fake ones that said my system was unsafe and that I should do this and that then download something to fix the problem. Managed a less than graceful exit.

Another option, but not without its' own issues,is a simple inline switch for the power cord.

Something like:

https://www.amazon.com/BindMaster-G...ocphy=9007868&hvtargid=pla-374453316394&psc=1

Not that switch per but a switch suitable to your electrical system and codes.
 
Apr 9, 2021
4
0
10
Likely an inline switch inserted into one of those 7 or 8 wires would be all that is needed.

Which wire (s) and what type of switch - no idea.

Are you using a breadboard? If so then you could easily test if one particular wire serves the power on/off function.

You might be able to trace along the PCB and wires to identify where the power button could be inserted.

However inserting a switch anywhere is a bit risky without fully knowing what each wire is for - a schematic is needed.

I did a bit of googling looking for applicable schematics, service manuals etc..

Found some links offering "manuals" but many looked very sketchy so did not click.

Did click one site that appeared hopeful but immediately got AV warnings etc.. Fake ones that said my system was unsafe and that I should do this and that then download something to fix the problem. Managed a less than graceful exit.

Another option, but not without its' own issues,is a simple inline switch for the power cord.

Something like:

https://www.amazon.com/BindMaster-G...ocphy=9007868&hvtargid=pla-374453316394&psc=1

Not that switch per but a switch suitable to your electrical system and codes.
Thank you for all the suggestions, especially the one with the inline switch for the power cord, this is a great last option! Unfortunetly I have never used breadboard.
I did a lot of googling as well and found that this website offers reliable information and the website is perfectly safe.
https://www.manualslib.com/manual/1114801/Lg-Flatron-L1932p.html#manual
The PCB with the buttons has almost this look, if this helps:
https://ibb.co/5GZ8QDg
Thank you again for your asnwer!
 

Ralston18

Titan
Moderator
Is one of the PCB buttons marked in some manner that can be identified as "Power" or "On/Off" , etc..?

Each button appears to have some labeling. However, I could not get any Zoom to get a good look at the PCB image.

I counted 7 buttons on the PCB board but only 6 wires leading away from the PCB board.

The key, for you, is to trace all of the wires about using the monitor's service manual and the on-site advantage of determining (eventually) what wires go where and through what components - especially the power button.

Use part numbers, diagram references, etc. per Manual Page 19 & 20. Much easier to map with the entire physical monitor sitting in front of you.

As for breadboarding that is a topic easily googled and you can easily tailor additional searches based on your current skills and knowledge.

The underlying advantage in your case would be a breadboard inserted between the PCB's output wires and the applicable monitor connector.

Normal PCB [Plug] ===> [Monitor connection port]

Inserting a breadboard:

PCB [Plug] ===> [Matching connector on breadbroad ] then use six jumper (tie points) wires to connect to a second connector that, in turn goes ===>[Monitor connection port]

Requires that you have the appropriate (1 x 6, gender) connector and plug for the breadboard . One of each gender with six ribbon wires coming out of the connector / plug.

Advantage being you do not have to cut any wires from the PCB with the buttons. Or desolder wires on the monitor etc.

You can change connection paths at will on the breadboard to see what works or does not work. There is some risk so do not do so randomly.

However, a carefully tracing of wires and connections should reveal where you can or may be able to insert a new power button.

Or if the PCB is proven faulty - maybe just replace the entire unit. Or go to "last resort".

Who know what else could happen on the old Flatron. You have options and only need to decide what trade-offs you are willing to make.....
 
Solution
Apr 9, 2021
4
0
10
Is one of the PCB buttons marked in some manner that can be identified as "Power" or "On/Off" , etc..?

Each button appears to have some labeling. However, I could not get any Zoom to get a good look at the PCB image.

I counted 7 buttons on the PCB board but only 6 wires leading away from the PCB board.

The key, for you, is to trace all of the wires about using the monitor's service manual and the on-site advantage of determining (eventually) what wires go where and through what components - especially the power button.

Use part numbers, diagram references, etc. per Manual Page 19 & 20. Much easier to map with the entire physical monitor sitting in front of you.

As for breadboarding that is a topic easily googled and you can easily tailor additional searches based on your current skills and knowledge.

The underlying advantage in your case would be a breadboard inserted between the PCB's output wires and the applicable monitor connector.

Normal PCB [Plug] ===> [Monitor connection port]

Inserting a breadboard:

PCB [Plug] ===> [Matching connector on breadbroad ] then use six jumper (tie points) wires to connect to a second connector that, in turn goes ===>[Monitor connection port]

Requires that you have the appropriate (1 x 6, gender) connector and plug for the breadboard . One of each gender with six ribbon wires coming out of the connector / plug.

Advantage being you do not have to cut any wires from the PCB with the buttons. Or desolder wires on the monitor etc.

You can change connection paths at will on the breadboard to see what works or does not work. There is some risk so do not do so randomly.

However, a carefully tracing of wires and connections should reveal where you can or may be able to insert a new power button.

Or if the PCB is proven faulty - maybe just replace the entire unit. Or go to "last resort".

Who know what else could happen on the old Flatron. You have options and only need to decide what trade-offs you are willing to make.....
Very detailed answer for which I will be forever in debt to you! I was not able to see any labeling on the buttons, however was avle to see letters on the PCB next to the button, like "menu", "power", etc. I have a lot of work in front of me regarding "how to use breadboard". I will be doing as you adviced very carefull wire/connection tracking to see what will come out of it.
I am afraid that the whole PCB is faulty as you suggested, I tried contacting mulitple authorized services for LG and LG itself for a spare part/new PCB, but they do not offer any unfortunnely. "The monitor is too old" they said.
Thanks for the suggestions, will try my best!
 

Ralston18

Titan
Moderator
You are welcome.

Poke about thrift stores, garage sales, yard sales, etc..

You may come across another LG monitor that you can use for parts. Maybe a smaller screen size but the PCB may fit the next larger monitor or two.

Not uncommon for some folks to scavenge about for old electronics... ;)

Good luck.