LG 22MP56 LED Display: Flashes on but then goes black

—-(((SOLVED)))—-

hi everyone its been about 30 hours and im back with a Vengeance!

so I took the darned thing all the way apart, separated the panel from the backlight, played around with all the different translucent layers, yadayada!

(done on carpet and very very gentle now)

plugged and unplugged all the cables over and over, Flicked and rattled all the little things on the board some, rolled up a paper tube and listened for where this little whining noise was coming from… but nothing seemed to be working the flashing backlight condition persisted.

so I was Testing this monitor using an old Sony Vaio laptop output via HDMI (brothers old laptop), turns out they had the same sized AC adapter barrell plug and were both about 19v (sony was 19.5 but close enough)

it stood to reason from the beginning that the monitor was not getting enough current. (worked on low brightness ‘checking for signal’ just fine) but try to power up fully and Blink, Blink, Blink.

long story short the 1.3a LG ac adapter (very puny looking) was the issue

the Sony Vaio 3.42A adapter fired the thing right up and its been working since!! EUREKA!!

snap everything back together, declare victory, go walk dogs in the rain, check out crawfish at the culvert puddle, eat some food and go to bed.

I suspect maybe someone had it at full brightness (perhaps to avoid the dreaded PWM flicker) and it aged a bit and the resistances grew and next thing you know 1.3 amps just wasn't quite enough.

anyhoo in searching for this Fix on the forums and such I notice it plagues many many displays out there not just this one, so I suggest anyone with a Flashing backlight seek out an AC adapter with a similar barrell size (and polarity, though most all nowadays are center pin positive) but higher rated current.

if you have one laying around that will work but has the wrong sized barrell tip, get some wire nuts and electrical tape and Clip em and strip em and swap em! save a few bucks and reduce the landfill mess! that's what im gonna do with this bad boy!!

(test the polarity with your multi meter to be double sure, otherwise it wont work and may spark a bit)

I’m going to test to see if the display will work on the original AC adapter when set at low brightness first, this is not possible without a spare adapter because the thing wont let you access the menus unless an input is plugged in.

(just another idea! if you aren't handy with wire strippers, or don't want to spend any more money on another AC adapter (about 7$ on ebay)

Thanks a lot everyone! I hope this helps you out in the right direction!