Sceptre X22WG-1080P Two Senconds to Black

[sparkythefiredog]

I have and x22wg-1080P bought from Costco April 20 2007. In June '08 it started to go black after two seconds on cold power up, flashlight confirmed that LCD was functioning, backlight just went dark. Power LED remained on.
I could get it to remain on if I powered it off with the button, turned it upside down and smacked it on the desktop a few times. It would then stay backlit when I powered it back up. Smacking it around any other way did not work.
So, I set the Windows screen saver to blank the screen, but not power down the monitor after 15 minutes of inactivity. This had the effect of leaving the backlight on but blanking the LCD, so I did not have to go through the monitor smacking exercise for months on end. Suboptimal, I know, but expedient.
This state of affairs went on for years until a couple of weeks ago when the backlight went hard dead after one of our infrequent AC power failures.
I figured it was a cold solder joint. I opened it up and spotted four cone top electolytics on the inverter board, a couple of them had vented.
I replaced all the CapXon 470uf caps with United Chemicon ELXZ250ELL471MJ16S. In my excitement of finding obvious problems, I forgot about my cold solder joint theory and did not heat up the transformer solder joints as I had planned.
The monitor worked fine for one day. The next day, I heard a high pitched whine from the monitor that rose in pitch and then went away as I cranked the brightness up. I thought OK, I can handle a brighter monitor, I have sunglasses if need be. :smile. The day after that the monitor went back to a solid two seconds to black issue.

A couple of questions.
Did I use the right caps?
How can I test the CCFL's without having another CCFL to replace?
I only want to take this thing apart one more time if possible.

Spark

[retiredcaps]

Originally Posted by sparkythefiredog

A couple of questions.
Did I use the right caps?
How can I test the CCFL's without having another CCFL to replace?

United Chemi-con LXZ are low ESR caps as per

http://www.badcaps.net/forum/showthread.php?t=2280

If smacking around the monitor made it come and stay on, you may have a soldering problem with the ccfl wiring?

"2 seconds to black" can be

1) bad caps
2) bad inverter transformer
3) bad ccfls and/or wiring
4) bad ccfl sense circuitry

See these pics for examples of #3

http://s807.photobucket.com/albums/y...klight%20lamp/

[sparkythefiredog]

Thanks RC,
I reviewed the pictures you referenced and opened the monitor back up. At first glance, the ccfls have none of the symptoms in the pictures. I'll pull off the kapton and look closer tonight.

The CCFL's look OK so far. I guess I should start to get familiar with sense circuitry and transformers. I'm saving up for a DVM, I'll ohm out the transformer and post that info when I get it.
Any pointers to theory of operation info for the sense circuitry?

Spark

[retiredcaps]

Originally Posted by sparkythefiredog

I'm saving up for a DVM, I'll ohm out the transformer and post that info when I get it.
Any pointers to theory of operation info for the sense circuitry?

In most cases, it is unlikely to be the sense circuitry. I would estimate 90% of the "2 seconds to black" cases here are items #1, #2, and #3.

If you around $20 to spend on a multimeter, there are some deals on ebay as per my post on

http://www.badcaps.net/forum/showpos...71&postcount=2

[alexanna]

Originally Posted by retiredcaps

In most cases, it is unlikely to be the sense circuitry. I would estimate 90% of the "2 seconds to black" cases here are items #1, #2, and #3.

If you around $20 to spend on a multimeter, there are some deals on ebay as per my post on

http://www.badcaps.net/forum/showpos...71&postcount=2

I would also start looking around your Craig’s list of other advertising for a monitor with a broken screen, you have a very good chance of getting a least 2 good CCFLs .These are usually not very expensive. I think of it as one of the tools I need to do the job.

[sparkythefiredog]

Sorry about the long delay, a couple of things have happened. My XFX 8800 GT XXX video card failed with five caps that blew their tops and spewed goo all over my pc mother board. I jumped on the Badcaps forum and found out that this is inevitable for those crappy caps. I ordered replacements for all the bad ones, and the ones that will go bad, from Badcaps. I just fininshed replacing all those, my video works great, thank you Badcaps. I can work on my X22WG again. I spent my meter budget on my video card caps, so I'm saving for that again now.
On a happier note, someone left a 24.6" Hannspree monitor out by their trash can on the road I live on. It has a two seconds to black issue, like my X22WG, but hey, now I have a test bed. The Hannspree has a problem with two burned CCFL wires that arced together. I tested the CCFLs from the Sceptre with the Hannspree inverter, they all work fine! This also means that the Hannspree inverter is probably OK. So I ordered a couple of CCFL cables from Guangzhou Guangdong for $2.83. That will take a while to arrive but worth the wait. I hope to have a meter in a couple of weeks.

[LA1]

I have the same monitor, when mine was new it use to buzz sometimes. I bought the monitor back in 2007. Now it will stay on for about 2 seconds, then I turn off/ on and on again for 2 seconds. This goes on for about 10 minutes till the monitoe gets warm, then it will stay on. What I found was 4 470uf 25v radial lead electrolytic caps puffed out. Not leaking yet. This wa on the power/inverter board...took a nice picture do not see any way to post the picture. I will but replacements from Mouse electronics.

[LA1]

found out I clicked quick post instead of reply here is the picture. The puffed up caps are to the right of the picture

[jetadm123]

LA1: Please use the manage attachments button to attach photos. Do not post them inline from an external site. I see at least 4 buldged caps that are probably the source of your problem.

[retiredcaps]

Originally Posted by LA1

here is the picture.

The preferred way to attach pictures is to use the manage attachment function so they are hosted here and not to post inline as they slow things down.

Capacitors die from age, heat, and shoddy build quality. Capacitors DO NOT have to be visibly bloated in order to bad. They can be out of tolerance uF (a 1000uF measures 20uF) and/or have high ESR (ohm). A multimeter will be insufficient to test for ESR. For that you need an ESR tester which costs between $50 and $300.

Most members here will recommend that you replace ALL the electrolytic capacitors with reputable brands from reputable sellers. Brands like Rubycon, Panasonic, and United Chemicon are suggested. A list of recommended caps can be found at

http://www.badcaps.net/forum/showthread.php?t=2280

[sparkythefiredog]

Hey LA1,
I have the exact same board in my x22wg-1080p. I replaced all the 470mfd caps on it and the little cap next to that giant capacitor. I looked at mouser too for the caps, their prices were good but their shipping cost was really high. I used Digi-Key to get the caps for my monitor. Buying from Badcaps is also cheaper than Mouser because of the shipping cost.
Does anyone know of sources for the transformers? I suspect that my issue will turn out to be a transformer, I'm thinking the high pitched whine I heard is before the latest issue is transformer related.

[retiredcaps]

Originally Posted by sparkythefiredog

Does anyone know of sources for the transformers?

ebay.com or http://www.lcdparts.net/IT.aspx

ebay is usually cheaper.

[LA1]

OK thanks for the tip about posting a picture. I used the insert image, so I guess that was not correct, where is the manage attachments.? . anyway here is a video on how to replace the caps
http://www.youtube.com/watch?v=6WDuDtAJozI