Sceptre X22WG-1080p monitor not staying backlit, Please Help!

[retiredcaps]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

How I tested the four CCFL's was with a 12.5" CCFL lamp from another monitor.

Going from a 22 inch ccfl lamp to 12.5 might be too much for a test? A 17 inch might be better, but let's assume the existing ccfls are good.

In post #1, you were ready to swap out the caps. If you have an ESR meter, measure the caps to see if they are within spec. If you don't have an ESR meter, you can try swapping out the caps to eliminate them.

What is the that multi pinned IC on the back side above point E/F?

[trex66]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

How I tested the four CCFL's was with a 12.5" CCFL lamp from another monitor. I just unplugged one lamp and plugged the spare into it. I did this with all four lamps. And I turned it on and off a few times ti verify the results. It's possible the lamp I used was too pulling too much power?

I have a few monitors around, but these only have one or two lamps, not a four lamp. Can I still use one to test the board?

[retiredcaps]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

Does this tell you anything?

Most inverter IC chips are designed to shut off the backlight if one or more of the ccfls are bad. Think of it as "all or nothing".

The test that you did is "valid" if one of the ccfl is actually cracked/broken or the wiring is completely open.

As ccfls age, they draw more power. If one ccfl draws too much power, the inverter IC chip, it will shut down all ccfls.

The easiest way to determine this is by using another lcd monitor. Do you have another lcd monitor?

[trex66]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

OK, tested the ccfl's. In the picture I've posted previously, the top two left ones were 2 and out. The next one in line, next to the transformer. Lit up for a second then went dim, then out. The last one, far right - was 2 and out, then once it flashed on then went 2 and out. Does this tell you anything?

[retiredcaps]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

If I'm doing this right, I got two with a 0.00 reading. The kids woke up and I haven't had time to pull these off the board and re-test.

Don't pull those diodes off. Let's move onto the ccfl testing.

[retiredcaps]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

Between the two yellow: 639.7
between the two blue: 641.7

They may be United Chemi-con caps, some are labeled KZE and others KZH

1) Your inverter transformer measurements suggests it is good.

2) The KZE and KZH are United Chemi-con caps. The little square crown is their symbol. Let's assume they are good for now and move below.

3) Do you have a spare lcd monitor? I suggest testing the ccfls next.

[trex66]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

OK, I'm still pretty much a newb. I'm trying to follow the guide posted, I'm not sure I'm testing the right components. If I'm doing this right, I got two with a 0.00 reading. The kids woke up and I haven't had time to pull these off the board and re-test. But, to tell the truth, I'm looking for something else to test, seems odd that both of these would go bad at the same time.

[trex66]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

Between the two yellow: 639.7
between the two blue: 641.7

They may be United Chemi-con caps, some are labeled KZE and others KZH

that is quite a post, I will wrestle with that tomorrow, step, by step - thanks

[retiredcaps]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

I took my PSU out and it is different than the ones pictured here.

It is not uncommon for manufacturers to make revisions and complete board changes under the exact same model number. This is why we *always* ask for pictures of your boards.

But this board is different, I have one transformer with leads on the corners. The resistance between the two left and the two right are almost exact.

See the attached pic. What is the exact ohms reading between the two yellow points? What is the reading for the blue points? Please post the measurements. They should be within 3% of each other.

The caps look good, I can't see any discoloration or physical damage to any of the parts on the board. Should I just go a head and replace the caps to eliminate them as the problem?

They look like United Chemi-con caps?

Bad caps can be a cause of 2 seconds to black. So can a bad inverter transformer. The other possibilities are bad ccfl lamp, bad ccfl wiring, and/or something wrong in the sense circuitry. See the guide (start with post #13)

https://www.badcaps.net/forum/showthread.php?t=10419

[trex66]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

I too have the same problem - display comes on for a second and then no backlight. I took my PSU out and it is different than the ones pictured here. I did what plainbill suggested and tested A-B, C-D, E-F, and G-H for resistance and there is none. But this board is different, I have one transformer with leads on the corners. The resistance between the two left and the two right are almost exact. But nothing between the top two and bottom two.

The caps look good, I can't see any discoloration or physical damage to any of the parts on the board. Should I just go a head and replace the caps to eliminate them as the problem?

[rokkaholik]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

Nevermind... Upon reassembly (AGAIN!) I got the blue power light, and then it went about it's flashing off and on with no screen flicker or anything. Just as I was about to set it aside, I looked down and had an idea. I had a spare PC sitting next to my main rig that I was redoing Windows on. I pulled the video cable from that monitor and plugged it in to this Sceptre and the damn screen fired right up and looks to be working perfectly. I'm not sure what just happened, but I'll take it.

[rokkaholik]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

Sorry I'm late... Long week of sickness at this house

[rokkaholik]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

When I was looking these up, there seems to be 2 different inverter boards that were put in this model of monitor. Mine is the 511GP just like the guy above posted pics of his board

[retiredcaps]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

I'll try to get pics tomorrow

#4 - looks like copy and paste error.

We want pictures to look like this

https://www.badcaps.net/forum/showpo...94&postcount=1

[rokkaholik]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

I'll try to get pics tomorrow

On a side note, not one of the caps that I did replace on the inverter board was popped, domed or leaking any funky crusty fluids.

[retiredcaps]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

Is it possible that the screen itself is blown out or is it the backlight on the inverter board?

Post pictures of your board so we can see your setup.

1) Post clear focused pictures AFTER reading

https://www.badcaps.net/forum/showthread.php?t=1868

2) Please do not post pictures inline as they slow down the loading of pages.

3) For best picture quality and clarity take your boards to a window on a sunny day, turn flash off, and use macro mode. Take a top down view of all your boards (front and back). Make sure the photo is legible so that we can read the PCB printing clearly. A shutter speed of 1/125 or faster will produce nice clear focused pictures. Try to get a photo that is 2000x2000 resolution or as close as possible.

4) Here is an example of the pictures we want.

https://www.badcaps.net/forum/showpos...94&postcount=1

[rokkaholik]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

I have this same monitor and there's not even the slightest flicker when I plug it in. Every cap on the inverter has been replaced. The power light comes on (no screen flicker) and then proceeds to flash on and off. There is no high pitched whining or ticking sounds coming from the inverter or any other piece.

Is it possible that the screen itself is blown out or is it the backlight on the inverter board?

[coulthrust]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

If you have proper test equipment it should be possible to repair this one. Certainly if the backlights stay on for a minute of two, troubleshooting it will be relatively easy.

Do you have a DMM? If so, the tests in post 5 are a good starting point.

PlainBill

OK thanks I will test those points and see what's up

thanks!

[PlainBill]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

I recently changed my caps but burned a bit of the circuit on one end. Your photo shows that it is indeed connected where I made a mistake, so now hopefully after I re-soldier them together, my back lights will come on. The black mark is where I accidentally burned the board and instead of a green circuit its goldish looking. Should I attempt to reconnect the two?

If they are really separated, yes.

PlainBill

[Lithorn]

Re: Sceptre X22WG-1080p monitor not staying backlit, Please Help!

I recently changed my caps but burned a bit of the circuit on one end. Your photo shows that it is indeed connected where I made a mistake, so now hopefully after I re-soldier them together, my back lights will come on. The black mark is where I accidentally burned the board and instead of a green circuit its goldish looking. Should I attempt to reconnect the two?