# [SOLVED] Post repair monitor problem



## drambit (Sep 17, 2012)

A few years back I bought an *Acer X193W 19" LCD* Monitor. It worked pretty flawlessly for about *1.5 years* at which point it had this problem of being on for a little while, then shutting off completely for some reason, yet I didn't look into it. Now that I know my way around electronics I tore the monitor apart a while back to see what was wrong. I think this is a *key mistake*, and probably what is causing my problem so I'll add this minute detail: While removing the Monitor's Power supply, I did a messy job *removing the Reflective tape* holding the PSU down. 

Anyway, I unscrewed the Power supply board and the main board (coincidentally about 1/5th the size of the PSU board.) I found that. just like most cases of failing monitor's, that there was a blown out 680uf 25v Capacitor on the power supply board. I found a good replacement Cap, replaced the broken cap etc., put it back together and everything was perfectly fine and dandy until the next day. When I turned my monitor on in the morning it started making this _Absolutely Un-bearable High pitched whining noise_. I didn't touch anything on the boards other than the busted cap. 

Can anyone help diagnose, and hopefully fix my problem? This isn't high priority for me because this is just a spare monitor, but this is really bugging the hell out of me. 

Thanks, Connor

PS: My Video Card is the Nvidia 9600GT, but I really don't think that detail matters, because my main monitor is running just fine.


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## Fish4Trout (Oct 16, 2009)

*Re: Post repair monitor problem*

How many times are you willing to tear it down, repair and reassemble, as you chase the falling string of dominoes of failing components? 

At this point I would be more inclined simply to replace the monitor. 
For example... 
Newegg.com - Computer Hardware, Acer America, LCD Monitors, 19"

If on the other hand, you are simply wanting to learn electronic repair...


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

As long as it takes me to fix it, or as long as it takes me to Lose sanity, whichever comes first. I'm not particularly interested in buying a new monitor, nor am I interested in learning per say, I just have a passion for *trying* to fix things. I have no problem continuously opening and replacing parts, I find that fun, as long as it doesn't cost me a lot.


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## makinu1der2 (Jan 1, 2008)

*Re: Post repair monitor problem*

Did you inspect the all the capacitors? Make sure there are none that are bulged or domed at the top.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

Yes obviously that's how I got it working in the first place. I think this is something to do with interference.


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## makinu1der2 (Jan 1, 2008)

*Re: Post repair monitor problem*

Was the same value capacitor used?

Usually the high pitched whine is caused by capacitors or the coil.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

I'm nowhere near dumb enough to replace a capacitor with a different value capacitor. That is a really stupid thing to do lol.


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## makinu1der2 (Jan 1, 2008)

*Re: Post repair monitor problem*

Just asking. I have seen it done before. It seems that you have all your bases covered sorry I couldn 't be of assistancc to you.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

I find it hard to believe that someone would take it upon themselves to replace a capacitor without knowing how important the amount of farads is.


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## JimE (Apr 16, 2009)

*Re: Post repair monitor problem*

The "obvious" fault is not always the actual fault. You are likely simply seeing the weakest link.

What you really need are schematics and test equipment. Other than that, you are simply guessing.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

Although it is completely true that the cap I replaced is probably just the weakest link, I'm inclined to think otherwise because, if I recall correctly. Before I replaced the blown cap, The monitor would just turn on for a small amount of time and then turn off, whereas now it functionally works perfectly but there is a loud screeching noise. I'd be happy to try and replace some big electronic coils or anything really, whether something else fails in the monitor after or not, but I want to try and figure out what it is. Essentially as long as it isn't a Microprocessor or actualy display panel I'm going to keep trying, I just can't diagnose the problem on my own.


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## Fish4Trout (Oct 16, 2009)

*Re: Post repair monitor problem*



drambit said:


> I'm not particularly interested in buying a new monitor, nor am I interested in learning per say, I just have a passion for *trying* to fix things. I have no problem continuously opening and replacing parts, I find that fun, as long as it doesn't cost me a lot.


Well... have fun then! 
(By the way... it is not "per say".)



> The "obvious" fault is not always the actual fault. You are likely simply seeing the weakest link.
> 
> What you really need are schematics and test equipment. Other than that, you are simply guessing.


NAILED IT!

<unsub>


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

You're right but I still want someone to guess for me


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## JimE (Apr 16, 2009)

*Re: Post repair monitor problem*

Components blowing is typically tied back to a power issue. Either the result of a short, fault, or just aged components. So I would concentrate on the power supply side.

Aside from that, I don't guess. Hence the comment about schematics and test equipment. Proper testing removes the guess work. If you want to "guess", then your guess is as good as anyone elses.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

I am looking at the power supply, I seriously doubt it would be anything else. And I know guessing is obviously unscientific, but you're wrong when you say my guess is as good as anyone else's. If you asked me to guess what's making a squealing noise inside my monitor I would come up with a blank, someone with experience might be able to guess what the problem is. Of course they may or may not be wrong, and it's not a good thing to rely on when fixing things, but I'm willing to give it a shot, that's why I am here. Can you take a shot at it?


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## Amd_Man (Jan 27, 2009)

*Re: Post repair monitor problem*



drambit said:


> I find it hard to believe that someone would take it upon themselves to replace a capacitor without knowing how important the amount of farads is.


I've seen that and much worse in my 16 years in the field. The questions asked where valid ones and they were just trying to help.


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## WereBo (Apr 5, 2008)

*Re: Post repair monitor problem*

Hi drambit and a belated welcome to TSF :wave:

Can you narrow down as to where the whining is coming from? Very many moons ago, when I was repairing B&W TVs with valves (tubes) in 'em, my 'mentor' used to use a cardboard loo-roll tube (or kitchen-roll tube) as a basic stethoscope to locate noisy components :wink:


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

What did he do just put it up to the screen or something? And I will try that later regardless, but Squealing is waay more common in CRT monitor's so I don't know if that will help.


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## WereBo (Apr 5, 2008)

*Re: Post repair monitor problem*

If you've seen the cartoons of nosey neighbours holding a glass to the wall, so they can hear what's going on, then substitute the cardboard-roll for the glass :grin: - Just hold the bottom end close (but not touching) to each area of the components (with t'other end to your ear) then slowly scan over all the internals.

On the old CRT-monitors (and TVs), the squeals were usually from either the HT-transformer or the 'yoke' on the neck of the CRT or, rarely, the mains-transformer.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

Alright. Should I do it while it's open?


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## WereBo (Apr 5, 2008)

*Re: Post repair monitor problem*

Yep and switched on, it's the only way to 'hear' each bit of the electronics. - At least it might narrow down where the noise is coming from, though what could make that noise is somewhat baffling, unless the monitor has a mains-transformer inside somewhere.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

Alright, I opened up the monitor, and tried to pinpoint where the noise was coming from via a toilet paper roll and my ear. If I have it right, the noise is coming from a "SPW - 078" Transformer on the power supply board. There is two of them, but they are only a couple inches apart so I couldn't tell if they were both making the noise, so If you think this might be the problem I can replace them both pretty easily. On the board there is also a bigger "SPW - 055" Transformer that is quite a bit bigger, but I didn't hear any sound coming from it.


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## WereBo (Apr 5, 2008)

*Re: Post repair monitor problem*

You might be able to detect which particular transformer is faulty by gently placing a finger-tip on the iron core (be very careful not to touch any of the connections though) and feeling for any vibrations - Check the transformer mountings if possible, the whine might just be caused by being slightly loose (if screwed or bolted down) or a 'dry' joint (solder crystallised), otherwise it'll (they'll) need replacing.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

No, I can't turn it on and have access to the pcb at the same time, the monitor isn't designed like that. The solder joints are also very nice, so I should just try and replace 'em eh?


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

I looked up the inverter on google and found that: 1: There is no mention of the Spw-078 B18KH Inverter anywhere on the internet, and 2: I did find an inverter called the spw 078 lse120 or something like that, but it costs almost $20 a piece. I don't know about this.


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## WereBo (Apr 5, 2008)

*Re: Post repair monitor problem*

Getting the wrong inverter can do more damage than what it's replacing being faulty can do, even with just a 1V difference here or there - Looking around the web, I could only find 1 site that sold the complete inverter/power-supply board for $40, but they were no longer available :sigh:

Short of replacing the entire monitor, I'm not sure what to recommend, other than contacting Acer and pleading with them for either the transformer or complete PS/Inverter board.


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## drambit (Sep 17, 2012)

*Re: Post repair monitor problem*

Nah I'll just get rid of it. This was just a pet project nothing worth spending more than $20 on.


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## WereBo (Apr 5, 2008)

OK then, I can't say I blame you :laugh: - If you're finished with the thread, you can mark it <Solved> using the 'Thread Tools' button, near the top-right of the page :wink:


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