Another LG Flatron W2243S-PF monitor - intermittent power issues

[thaphatmaster]

Afternoon all,

Firstly, I'm glad I found this place via Mr Google.

My LG Flatron W2243S-PF has had an intermittent fault for a looooong time The fault is:

1. It simply turns off during use; or
2. refuses to turn on, and
3. flashes its red power light.
4. It sometimes does this multiple times a day;
5. it sometimes does this for weeks on end; and
6. it sometimes works completely fine, for days or weeks on end.

It's now in a period of having this fault, which is making it nigh on unusable. I am keen to repair it as I have lots of cool Nerf Gun 3d printing projects to get on with using CAD software, and it's my biggest monitor.

I am reasonably experienced with a meter / soldering iron from various projects (and volunteering at a local repair cafe), but my level of electronics knowledge is by no means expert.

So, although I am not having 2 seconds to black issues, I have the correct tools:

a) a multimeter
b) camera to take clear focused pictures
c) solder iron to replace components with optional desolder wick or pump

and personality traits

a) ability to follow directions
b) some troubleshooting skills
c) determination
d) willingness to learn
e) patience

... to have a crack at fixing the monitor.

I came here because Mr Google suggests the caps might be bad. I have taken the boards out and there are no obviously damaged components, though some of the solder joints look dry, or bubbly.

I see from other threads that images are desirable. Happy to provide those, but I'd like some direction as to what photographs to take so I don't just spam the thread with images.

[CapLeaker]

Re: Another LG Flatron W2243S-PF monitor - intermittent power issues

First off, welcome to Badcaps!
We do need to see pictures of your boards. Make sure that they are high resolution and straight shot and upload them as an attachment. This won’t spam the thread, as the full pictures won’t automatically load.

[thaphatmaster]

Re: Another LG Flatron W2243S-PF monitor - intermittent power issues

First off, welcome to Badcaps!

Thanks for the welcome, this seems like a great and supportive place. I've attached some photos:

• the overviews were taken on my wife's DSLR;
• the close ups of various solder joints on the power board were taken on my phone with a cheap generic MACRO attachment.

The signal board was hard to focus on with the big camera (photography tips welcome!). In any event I'm happy to take MACRO shots of any specific components.

Thanks again,

Steve

[CapLeaker]

Re: Another LG Flatron W2243S-PF monitor - intermittent power issues

As for camera tips, all I ever use is my iphone or ipad's camera, thats it. Works the best and fastest for me. Yes I do have a DSLR and macro lens, but still, the iphone's camera is sufficient and fast.

Since your problem is erratic at best, I'd go looking for bad solder joints first. Looking at your power supply picture #2 (bottom) I see dry / cracked / rings on some solder joints. Resolder everything that looks shady, has a heat sink on it and the transformers (weight).
Sometimes heat (wifey's hair dryer ) comes in handy heating parts of the power supply (just don't over do it) also don't forget to give her the hair dryer back! Freezing (a can of air upside down) also can help you find a problem.
If the monitor won't start because its cold, heat up the capacitors and see if it will turn on. If the monitor is hot and it shuts off, could be an IC cold solders etc.

There isn't anything BGA, so no need to reflow any boards in the stove.

[thaphatmaster]

Re: Another LG Flatron W2243S-PF monitor - intermittent power issues

Thanks @CapLeaker, I've reflowed the dodgy bits (no pic yet because the resolution it too big, even from a phone which is frustrating, and I haven't got time to resize) but am yet to reassemble the monitor (small baby providing a happy distraction) - fingers crossed

[thaphatmaster]

Re: Another LG Flatron W2243S-PF monitor - intermittent power issues

So far so good, only time will tell

[thaphatmaster]

Re: Another LG Flatron W2243S-PF monitor - intermittent power issues

Oh dear - after a run of three months trouble free - the dreaded blinky red light is back.

The PC seems to recognise the monitor - my (Linux) WM assigns it workspaces, and my mouse goes up there - however it's blank, and the red power light is blinking away.

[TechGeek]

Re: Another LG Flatron W2243S-PF monitor - intermittent power issues

Oh dear - after a run of three months trouble free - the dreaded blinky red light is back.

The PC seems to recognise the monitor - my (Linux) WM assigns it workspaces, and my mouse goes up there - however it's blank, and the red power light is blinking away.

Might ought to re-open it and see if the same solder joints have went cold again and/or if more solder joints have went cold. Also, can you please post photos of the capacitors in the monitor?


Thanks.