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Old 04-26-2012, 02:51 PM   #1
Jasgriff
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Default Acer x221w

Had 8 of these to fix with my most recent batch.

When I cracked open the first one for testing it was lighting up one CCFL and only half lighting up the other one. When I stripped it down and took out the power board I could see that the were some burn marks on the transformer.

On testing the transformer the burnt side was shorted. I then tried another monitor and this was also suffering from a blown transformer. As you can see there was a bit of a theme going on with them.

It turns out 4 of them had completely blow transformers and one of them is making a noise so it is definitely on its way out.

I managed to get the others working by swapping parts from the boards with the faulty transformers. 1 of them had a fine transformer but a blown mosfet. One had a faulty logic board and believe it or not one of of them someone had disconnected the front panel of buttons which meant it wouldn't turn on. Once reconnected it powered on and worked fine.

I have got a deal on 10 transformers for 27 from china so I am sure I can get the others up and running when the transformers arrive. Then I can work on the not so easy faults and see if I can get them all up and running.

I will add a few more pics of the burnt power supplies and mosfet later.
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Old 08-24-2012, 03:27 PM   #2
Jasgriff
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Default Re: Acer x221w

Hi All,

Not been on for a while. Hope all are well!

Had another one of these to fix. The monitor was fully lighting up one CCFL but the other was only half lit. I assumed that it was the same as all of the other versions of this that I have fixed and changed the inverter. On testing all CCFL's works and I put the monitor back together and it was working fine. I left it on for a while to make sure that all was ok but it seems to be making a buzzing noise?

I have a feeling that if I leave it on it will burn the inverter like what happened to the last one. Does anybody have any thoughts on what might be causing this? Filter cap maybe?
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Old 08-24-2012, 04:35 PM   #3
retiredcaps
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Default Re: Acer x221w

Quote:
Originally Posted by Jasgriff View Post
I left it on for a while to make sure that all was ok but it seems to be making a buzzing noise?
I fixed a LG 22 inch monitor recently and put it all back together and have the same buzzing noise. It goes away after about 10 minutes of use.

The picture quality of the LG is so bad though (even adjusting all the settings), I haven't taken it apart to see what is causing the buzzing, but it could be an internally frayed connection ccfl wire?

It could also be bad solder joints on the inverter transformer, but I probably won't be looking at this monitor again until fall/winter starts.
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Old 08-24-2012, 04:42 PM   #4
Jasgriff
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Default Re: Acer x221w

Yeah thinking about it if there was a cold joint or a poor connection then I suppose it could make that noise.

I will crack it back open and check that. I can try a different set of CCFL's on it at the same time I suppose.

The picture quality on the Acer is ok. I just want to get it running and out of the way to make some space.
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Old 08-24-2012, 04:59 PM   #5
retiredcaps
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Default Re: Acer x221w

Quote:
Originally Posted by Jasgriff View Post
The picture quality on the Acer is ok.
Normally, I'm not picky at all about picture quality. After all, my "main" two monitors are freebies discarded by others and repaired by me.

But the LG is so bad, it is noticeable. I suppose I also might trying cleaning and reseating the cables as well, but it won't help the buzzing, but might help the picture quality.
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Old 08-24-2012, 06:11 PM   #6
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Default Re: Acer x221w

If you have AM radio tuned to a blank reception then put it close to the panel and see if you can hear real nasty noise on the radio. Try it with good working monitor so you can tell what the normal, non-arching, sounds like.
Usually if it is arching, the radio will not even have to be real close to the monitor to pick up the noise.
I ran into half lit lamp problem, it turns out to be one of the two windings has 3K of resistance instead of 1k, but still enough to light up the lamp, but the inverter go into shutdown after 3seconds, long enough to see that the lamp is not fully lit. Smae symptom with bad ballast caps also.
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Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/

TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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