Monitor does not turn on, no power or lights.

[Bobofwoggle]

I just got a second hand computer monitor, and it doesn't turn on. When I plug it in and press the power button, it doesn't even flash the power indicator.

I opened it up and can't seem to find anything amiss. No bulging or leaking caps, no bad solder joints, nothing. I managed to get it to turn on exactly once, while it was open. It showed the "no signal" screen for a minute, then shut off.

[strike]I have no idea what the problem is, seeing as I'm an idiot, and hope I could get some help.
[/strike]
I suspect one of the caps is actually faulty, just not visibly, although that leaves the question of why it turned on that one time. If it's not, or if I can't fix it, oh well, I got the thing for free and there's more where that came from.

EDIT: completely forgot to specify what model and everything, thanks for pointing that out. It's an LG L194wtx-bfq. No idea how old it is or what it's been through.

 

[Ralston18]

Well, to start with: you are not an idiot. More likely a victim of Mr. Murphy.

You did not mention the age, condition make or model of the monitor.

You took a chance on a used product that may have "given up the ghost" at a time inconvenient and unfortunate for you.

I applaud your ability and willingness to open the monitor up and poke about.

Get the manual and the schematics if you can.

Poke about a bit more, check the power button, verify the power and video cables, and the power supply. Any internal fuses?

See if anything turns up and, if not, write the montor off and move on.

 

[DeadlyDays]

loose wire/connector to power button? Nothing happened when you hit power while all put together, but after you took it apart and had it open it did start up. You probably bumped something that is making a poor connection/etc. It may have turned off because the connection just barely is making contact now, and is going in/out and that is like turning it on/off now, but wasn't a close enough connection before taking it apart.

Seems most likely based on your description yes?

Besides that, the most common failure on modern LCD screens(pre LED backlit) is the CCFL backlights burning out. It starts out with the monitor display "turning off" after awhile of being on, and the time itll stay on decreases(but the power never goes out on the monitor, just the display). You can test/prove that particular issue by shining a bright light into the screen and the reflection off the backside will shine back through and you'll see what's on the screen at that moment. Just an FYI if you encounter other issues besides the turning it on/keeping it on issue.

CCFL bulbs are not too expensive and you just solder them in. You'd have to buy them online in the right size though.

 

[Bobofwoggle]

loose wire/connector to power button? Nothing happened when you hit power while all put together, but after you took it apart and had it open it did start up. You probably bumped something that is making a poor connection/etc. It may have turned off because the connection just barely is making contact now, and is going in/out and that is like turning it on/off now, but wasn't a close enough connection before taking it apart.

Seems most likely based on your description yes?

Opened it up again and found that the wires connecting the buttons to the mainboard were busted at the connection. Did some fiddling and now the monitor works, but the button inputs are jumbled (pressing what's supposed to be power brings up the menu, the input button starts auto-adjust, and none of the others work). But again I got the thing for free so no real complaints here.