ancient monitor, the "wind" might be unstable supply voltage - needs new electrolytic caps

Uses 4 x CCFL tubes for backlight ..my guess is they're failing (along with associated power supply section)

rasz_pl wrote on 2023-12-24, 02:10:

ancient monitor, the "wind" might be unstable supply voltage - needs new electrolytic caps

giantclam wrote on 2023-12-24, 03:00:

Uses 4 x CCFL tubes for backlight ..my guess is they're failing (along with associated power supply section)

I've since checked some repair videos and they're all regarding the power supply's caps. The disassembly and task itself seem within reach of my abilities, so I'll give it a shot in the near future.

As for the CCFL tubes I haven't seen a further disassembly beyond the PSU or any video regarding that so I'm unsure how to approach it if needed. But anyway this monitor was always used with a lower brightness than usual so I might have a shot at more longevity if the PSU's issues are solved, I guess I'll start there and see.

Many thanks to you both!

Tube failure usually starts manifesting by blue/pink color tinge in the picture. At this points its much easier and cheaper to just buy another panel, 19 inch ones sell for scrap value anyway.
Weak power supply caps symptoms are problems starting up, and initially only working after warming up with progressively more and more time required to get it going. Sometimes changing backlight to full 100% helps temporarily, sometimes lowering way down. Capacitor job is the easiest fix one can perform and a great way to get into hands on electronics. You dont need any fancy expensive super branded premium replacement caps, any 'low esr' will work fine for few years minimum.

This definitely sounds like bad capacitors and it shouldn't be difficult to fix. One does have to pay attention to that big capacitor on the primary side of the PSU when going inside the thing, it can hold a charge that is potentially deadly (this applies to pretty much all the power supplies you will encounter).

In my opinion, those who advise you to replace the capacitors are right, probably by opening the monitor, there are one or more of them swollen, but it doesn't mean that the others, even if they seem fine, are not leaking, changing them should not be too complicated , and you could fix it, but as Tiido suggests, you have to pay attention, in the primary even if you have turned off the monitor, there remains a charge that must be discharged, before carrying out any work, which I would do in any case without the power cable connected.

Thanks for confirming the issue everyone, I'll prepare myself a little more and have a go at it.

Today it started working faster than usual with no "wind" actually, but the brightness is now too high by default and stays that way no matter what I adjust in terms of values. Throughout these last two months it started turning on with increasingly more "wind" as time went by, but always ended up with a perfect image after a minute of two. So I guess I'll tackle this sooner rather than later.

Obviously a replacement 19" should be cheap, it's just that this monitor is part of a build with sentimental value, so I'll do what I can for now and see how it goes

Tiido wrote on 2023-12-24, 21:08:

This definitely sounds like bad capacitors and it shouldn't be difficult to fix. One does have to pay attention to that big capacitor on the primary side of the PSU when going inside the thing, it can hold a charge that is potentially deadly (this applies to pretty much all the power supplies you will encounter).

rasz_pl wrote on 2023-12-24, 18:23:

Tube failure usually starts manifesting by blue/pink color tinge in the picture...

PC@LIVE wrote on 2023-12-24, 23:10:

In my opinion, those who advise you to replace the capacitors are right, probably by opening the monitor, there are one or more of them swollen, but it doesn't mean that the others, even if they seem fine, are not leaking, changing them should not be too complicated...

So I went ahead and replaced all capacitors on the PSU board, and the smaller VGA board. The good news: the "wind" is gone, crystal clear picture, monitor starts up every single time and behaves as normal. As for the bad news, the red/pink tinge in the picture remains. It definitely isn't a calibration issue as I have to change the values to absurd numbers to get it 90% there, but the tinge is always noticeable to a degree, tested with different cables, computers, etc., it really is the monitor itself.

giantclam wrote on 2023-12-24, 03:00:

Uses 4 x CCFL tubes for backlight ..my guess is they're failing (along with associated power supply section)

Whatever the case may be it was a cool experience to prove to myself that I could do this to which I have your encouragement to thank for, I would just like to ask if this is related to the CCFL tubes that were mentioned, and how would I go about replacing them, or if not if you could please point me out towards possible causes that I could still explore.

As I said I do realize of course that a 19" monitor can be had for cheap these days, I'd just like to know if there is anything else I can do within my abilities in order to save this one which has sentimental value to me.

As always thank you so much!

As rasz_pl noted above, a pink tinge is typical of CCFL tube failure (not actually failure but wear) ~ if you search youtube on this, you'll find images of the pink/red CCFL worn tube look =)

As for replacing them...I'm not familiar with that unit, but typically you have to dis-assemble the display panel...hint: this is NOT fun.

It ends up being BER (beyond economical repair), because on ebay you can find 2ndhand business type displays like this for around $50 ...ie; HP LA1956x (with builtin 2 port USB hub)

andre_6 wrote on 2024-01-03, 00:22:

Whatever the case may be it was a cool experience to prove to myself that I could do this to which I have your encouragement to thank for

skill unlocked 👍

andre_6 wrote on 2024-01-03, 00:22:

I would just like to ask if this is related to the CCFL tubes that were mentioned, and how would I go about replacing them, or if not if you could please point me out towards possible causes that I could still explore.

Yes, as mentioned by others worn out tubes, on some monitors you can enter service menu and see hours counter.
First step would be locating replacements, and thats pretty much impossible nowadays. Your best bet for sourcing correct CCFLs is finding same model monitor with cracked screen and hoping its 1 same panel 2 low hours, you could maybe risk another monitor with same size panel hoping lamps will just fit.
What you can still find are LED strip kits. Most basic LED backlight panels just use LED strips mounted in the place CCLF used to live.
https://people.xiph.org/~xiphmont/thinkpad/le … backlight.shtml https://people.xiph.org/~xiphmont/thinkpad/led-panel.shtml
Replacement involves opening LCD Panel (its not build to be serviceable so a high degree of improvisation is in order) and stripping it down to basic components. You will also need special led strip power supply accepting brightness control, cant reuse ccfl supply.
Things that can and will go wrong
-tearing off flex signal tape glued to glass panel
-ripping said flex, damaging chip on glass/chip on flex buffers on the flex
-leaving dust/hair/animal fur inside the panel. This got me twice when I opened my first one, not fun.
-not working brightness control
-bad colors after replacement
-light bleed/uneven backlight after replacement

all in all its multiple hours of work for ~$10 19" lcd monitor https://allegrolokalnie.pl/oferta/monitor-lg- … tron-w1942s-rwd

giantclam wrote on 2024-01-03, 00:39:

As for replacing them...I'm not familiar with that unit, but typically you have to dis-assemble the display panel...hint: this is NOT fun.

It ends up being BER (beyond economical repair), because on ebay you can find 2ndhand business type displays like this for around $50 ...ie; HP LA1956x (with builtin 2 port USB hub)

rasz_pl wrote on 2024-01-03, 01:52:

Yes, as mentioned by others worn out tubes, on some monitors you can enter service menu and see hours counter.

all in all its multiple hours of work for ~$10 19" lcd monitor https://allegrolokalnie.pl/oferta/monitor-lg- … tron-w1942s-rwd

Thanks for clearing it up for me guys, I just wanted to be sure that I had done everything that I possibly could within reason and my beginner abilities. Out of curiosity I checked the service manual and accessed the service menu but it didn't had the hours of usage available.

However I've had this monitor since 2008, by my rough estimations it's probably hitting the 50.000 hour mark, so I guess it's rightfully earned its retirement. I suppose it fully deserved this last effort from my part to show it some respect.

Thanks everyone, wishing you all a happy 2024!