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

[ben805]

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

Hi, I know this is an old issue, but I am having the same problem. Does anyone know where I can purchase an inverter board for the Sceptre X22WG-1080P?

[Mad_Professor]

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

try soldering it again perhaps you got a cold joint.

[trex66]

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

Yes, I wanted do that today, I have to find a good magnifier and see where the trace goes. It's been a while but I must have checked it when I re-soldered it... I will post when I am able to test it.

OK, checked the pin and it has continuity to, looks like J1 next to it. Phisicaly it looks good but I'm not sure if I could have damaged it when I unsoldered it and then soldered it back down - I know some components are more sensitive to heat than others.

I don't know what else to look for on here...

[Mad_Professor]

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

For anyone trying to help me, the pin I'm worried about is the #16 pin from the BIT3193 it is the MODSEL output "to set the output polarity of the low frequency PWM controller" does anyone think this could be my problem?

That solder pad for 16 looks nonexistent.
Trace pin 16 and solder pad to the next component and see if it's getting continuity if not you will have bridge it.

[trex66]

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

For anyone trying to help me, the pin I'm worried about is the #16 pin from the BIT3193 it is the MODSEL output "to set the output polarity of the low frequency PWM controller" does anyone think this could be my problem?

[trex66]

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

OK, I'm back with a new problem. My sceptre originally was a 2 seconds to black and finally found I had a bad ccfl - Anyway, I put it all back together and fired it up and... worked except the colors on the screen were all washed out. There is no color saturation, looks like the brightness was pushed up 200% and the type on the screen is out of focus and hard to read. Hard to take a picture showing it because it looks like I was using a flash. I was sick of this monitor and put it in the basement. I decided to fix this or throw it out.

Thing is I have been all over this monitor, the power/logic bd and I replaced the ccfl. My worry is that it has something to do with the one leg on the ic I pulled up and then re-soldered. I re-seated the cable connections hoping it could just be one pin not connecting...

so, again I am here asking for any help or direction

I put some screen test colors on the monitor and it appears to me that the problem is with the black, which is grey. The other colors Cyan, Magenta and Yellow are bright and vivid

[alexanna]

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

Probably best to junk it, and buy a new one then?
or can the CCFL's be replaced for a reasonable price?

If you're going to junk it send it my way.
You really need to figure out what is causing the 2 second to black problem; it could be as simple of repairing a solder connection on one of the CCFLs.

[YZNHMR]

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

Probably best to junk it, and buy a new one then?
or can the CCFL's be replaced for a reasonable price?

[alexanna]

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

"
what is the next step?

The quickest and easiest way would be to substitute a panel with known good CCFLs.You just need to hook up the bulbs, If that is not possible try substituting 2 good CCFLs at a time in all the combinations possible.
As long as the connectors are the same, I have used a panel from a 15” monitor and have had very good results

[PlainBill]

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

" If all worked at the same brightness you probably have a problem in the inverter; specifically in the monitoring circuit."

if this is the case, then what is the next step?

It almost doesn't bear thinking about. There are a couple of dozen components that take the signals from each CCFL, combine them, and feed them to the inverter controller. We have to try to identify which CCFL is causing the problem, then compare signals at various points to isolate the suspect components.

Note that my original post was written nearly a year ago. In that time we have discovered that one or more bad CCFLs are a very common cause of 'two seconds to black'.

PlainBill

[YZNHMR]

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

Well, that sucks. I see five options at this point:

1. Borrow a DMM (or have a friend check it for you).

2. Buy a DMM. Harbor Freight Tools sells a rather nice one for $25. Fluke sells VERY nice ones for somewhat more.

3. Give it to someone who has the capability of repairing it.

4. Send it to the landfill.

5. Try these tests. This MIGHT damage the inverter. For simplicity we will label the CCFL wires from the inverter as A, B, C, D. The wires to the CCFLs will be labeled 1, 2, 3, 4. Normally A connects to 1, B to 2, C to 3, D to 4. We will describe this as A1, B2, C3, D4. Got it?

Disconnect B2, C3, D4. Now the A output is the only one connected to a CCFL. Position the panel so you can see the face of it. Plug the monitor in and cycle the power button (press it twice, pausing a second or two between presses). Does the screen light up briefly? If yes, estimate it's brightness, then disconnect A1 and hook up the B2. Cycle the power button. If it lights up, is the brightness about the same as A1? Repeat this for the remaining CCFLs. If all worked at the same brightness you probably have a problem in the inverter; specifically in the monitoring circuit.

If a lamp did not light, or was dimmer, you have to figure out if the problem was the CCFL or the inverter. As an example, we will say that B2 was much dimmer. Now hook B to 1 and cycle the power button. Is the CCFL now at full brightness? Try hooking A to 2 and cycling the power button. Is it now at full brightness?

If a CCFL (1, 2, 3, 4) will not light at full brightness no matter which output it is connected to, there is a problem with that CCFL or it's wiring. If an output (A, B, C, or D) will not light a CCFL at full brightness you have either a bad solder joint or a bad transformer.

PlainBill

" If all worked at the same brightness you probably have a problem in the inverter; specifically in the monitoring circuit."

if this is the case, then what is the next step?

[alexanna]

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

trex66,
I think you have more than one bulb giving you a problem.Alot on monitors I see develop a problem where the small white wire solders to the ccfl,They are usually discolored, and brittle .
When you order your parts I would suggest getting at least on extra ccfl in case you need it.
As an added bonus if you have time could you redo your testing with the smaller ccfl when you get your new ccfl installed? To see if we can use the shorter bulb for testing.
Al.

[PlainBill]

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

My wife is making me do the Atkins diet with her. I'm sitting across the table from her wondering what I ever did to her and what I'm going to do - but something kept bothering me and it wasn't just the food.

The Atkins diet promotes weight loss by depriving your body of vital nutrients. While this may be effective in the short term, it is very unhealthy. Perhaps if you point out to your wife that if she continues on this diet her face will develop wrinkles, her body will sag, and her hair will fade she will reconsider her approach.

Congratulations on the monitor diagnosis.

PlainBill

[retiredcaps]

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

That 12" test lamp must not have been pulling enough current to keep the lamps lit.

Yes, that was what I was worried about. Some have had luck with 17 inch ccfl in a 22 inch monitor.

Glad you found the problem.

[alexanna]

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

Great!!!! glad you found it
Al.

[trex66]

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

My wife is making me do the Atkins diet with her. I'm sitting across the table from her wondering what I ever did to her and what I'm going to do - but something kept bothering me and it wasn't just the food. Those screwy CCFL's! They act one way one day then different the next. Then I remembered I had an old Apple laptop with the same plug and the inverter right under the hing cover. I plugged each of the four CCFL's in to the inverter and yes, one wouldn't light up. Now I'm happy, I don't care what I was just fed, I took the screen apart and there it was, a big beautiful black hole in the lamp. That 12" test lamp must not have been pulling enough current to keep the lamps lit.

I consider myself a regular guy when it comes to intellect. And I've tried, but for the life of me I can't get my head around this stuff. I know what most of the components do - but how they interact as a whole and make radios or computers do what they do is beyond me.

Anyway, my thanks to everyone here. Thank you for your patience, explanations and most of all, thank you for not laughing at me. This is a great board, you guys are helping a lot of people and saving a lot of electronics from the trash heap.

[retiredcaps]

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

10-16 0.2 Ω

This, by far, is my weakest area of troubleshooting (the sense circuitry) and I could be leading through a wild goose chase, but we now know that out of circuit pin 10-16 is 50K ohm resistance. In circuit is 0.2 ohms.

Now either this is by design or not. Let's assume it is not. So try tracing the circuit path (with power off and lcd unplugged) from pin 10 to pin 16 using your continuity feature on your multimeter. See what components it is going through to get a 0.2 ohms reading. This may give us a clue on a component that is possibly shorted?

[trex66]

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

When you're doing the testing with your spare ccfl do you have a video source connected?
The ribbon cable to the LCD panel does not have to be hooked up.
Al.

Yes, I couldn't get the monitor to try to start up without a VGA cable connected.

[PlainBill]

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

OK, ran the monitor through every combination of my spare CCFL and the other four leads. This time I couldn't detect any difference between any 2 and off cycles. I tried to reproduce what happened yesterday, but I couldn't. I would like to write off the CCFL's but I know the test CCFL I have is not the same size as the ones in the monitor and it came from a used screen.

I re-tested the surface mount components I couldn't get a reading from and I got a 55.76 KΩ for the resistor but still nothing from those two caps...

Depending on the circuit, a capacitor will read open when using the resistance ranges on a DMM.

PlainBill

[alexanna]

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

OK, ran the monitor through every combination of my spare CCFL and the other four leads. This time I couldn't detect any difference between any 2 and off cycles. I tried to reproduce what happened yesterday, but I couldn't. I would like to write off the CCFL's but I know the test CCFL I have is not the same size as the ones in the monitor and it came from a used screen.

I re-tested the surface mount components I couldn't get a reading from and I got a 55.76 KΩ for the resistor but still nothing from those two caps...

When you're doing the testing with your spare ccfl do you have a video source connected?
The ribbon cable to the LCD panel does not have to be hooked up.
Al.