MAG Innovision LT716s 700p 2 Seconds To Black

[JadeMattican]

First Off, This Monitor Was A Freebe & I Do Not Know It's History Other Than The 2 Seconds To Black.

What I'm Posting For Is An Opinion. Should I Replace ALL The Caps On BOTH Boards? Or Should I Just Replace The Caps On The Power Board.

Yes, I Have Looked At The Troubleshooting Guide For 2 Seconds To Black By RetiredCaps @ https://www.badcaps.net/forum/showth...ds+black+guide. There It Mentions, "You turn on your LCD monitor and it displays an image of your screen and then suddenly it turns off after 1 or 2 seconds. The power LED stays on (or green) and you can still see the image by shining a flashlight on it."

When I Tried With A Flashlight, I Saw Nothing.

Understanding That The Caps Do Not Have To Be Visibly Bad To Actually Be Faulty, I Pried The Screen Open To Find 4 Different Brands Of Caps... Xunda, YEC, Leaguer, And 1 Big One That Was Glued Down. None Appear To Be Bad, But The Xunda And The YEC Were Listed On The List Of Bad Caps.

In Addition, I Do Not Have Any Additional CCFLs To Test With. As Such, I Stripped The Screen Down To See If There Were Any Visble Signs Of Failure. I'm Thinking That This Is The Issue (See The Last 2 Pics.)

Thanks For Your Time.

[retiredcaps]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

When I Tried With A Flashlight, I Saw Nothing.

In Addition, I Do Not Have Any Additional CCFLs To Test With. As Such, I Stripped The Screen Down To See If There Were Any Visble Signs Of Failure. I'm Thinking That This Is The Issue (See The Last 2 Pics.)

1) Just a readability note. Try not to capitalize the beginning of every word. It makes it hard to read.

2) Did you have a computer displaying your favourite wallpaper when you did the flashlight test?

3) Before recapping anything, do you have a multimeter to try the transformer test?

4) The ccfl tubes don't look obviously bad, but the wiring could still be at fault. I recommend trying the transformer test first.

[EGuevarae]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

1) Just a readability note. Try not to capitalize the beginning of every word. It makes it hard to read.

2) Did you have a computer displaying your favourite wallpaper when you did the flashlight test?

3) Before recapping anything, do you have a multimeter to try the transformer test?

4) The ccfl tubes don't look obviously bad, but the wiring could still be at fault. I recommend trying the transformer test first.

1.- I second the #1 suggestion.
2.- Leave the signal board alone.Concentrate on the power/inverter board.
3.- It may be the lamps,but since you don't have another set to test,I would start recapping the power board, since it should be recapped anyway ...
4.- Welcome to the forums.

[FIXITNOW]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

do and check this list
"1. Re-Solder both Transformers.
2. Re-Solder any joint that looked cold under a Magnify Glass.
3. Replace the following caps:use panasonic fm series or simular low esr
2 - 10MFD 50V C3, C25 5mmx8mm
2 - 100MFD 35V C10, C11 8mmx11.5mm
6 - 470MFD 25V 10mmx16mm
1 - 220MFD 25V 8mmx12mm
1 - 47MFD 50V 6mmx11mm"

[alexanna]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

There are some monitors that is very difficult to tell if a image is present after the ccfls go out.
Your ccfl tubes look OK in the picture, you might want to inspect the return wiring where it is soldered to the bulb. Any discoloration is an indication of a problem.
If you still have the panel dissembled, you could plug the ccfls back in and see if the brightness looks the same on all the bulbs during the two seconds to black problem.
Al.

[sabre504]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

Same setup as Xerox x7 19"

[JadeMattican]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

@ RetiredCaps

As to the readability note, it's a habit that goes back a ways... I'll try to refrain.
The display was the default Win7 Pro background. And, yes, I do have an old digital multimeter. As far as I know, it still works the way its supposed to work. I've never tested a transformer, but will try it & let you know the results.

@ Eguevarae

I figured as much about leaving the signal board alone, but wasn't sure. Assuming the transformer tests ok, then I'm off to buy new caps. Thanks for the welcome.

@ FixItNow

Thanks for the list of caps! As to the cold solder joints, I think I know what I'm looking for...

@ Alexanna

That's a great idea...Now, to see if I can get it back together enough to test without frying anything.

[retiredcaps]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

To test the transformer, see

https://www.badcaps.net/forum/showpo...1&postcount=14

[JadeMattican]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

Many thanks for the link...

Here's an update with pics... Why am I so easily amused?
The first pic is the screen with a led flashlight behind it. The second pic is the screen with a fluorescent bulb behind it... Simply put, it works... Sort of. The third pic is just to show how far disassembled the screen is.

On another note, of the 4 CCFLs, 1 of them does not seem to be quite as brite as the others... It's just barely noticeable though. I'll try to get a pic of it... 2 seconds isn't a lot of time though...

[JadeMattican]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

Bad idea tyring to take pictures of bright lights...(Might as well have spent the time trying to take pictures of UFOs or bigfoot... No offense to anybody who has seen either.

I believe that the CCFLs are the main issue. I will test the transformer while i have it open & attempt to replace the bad bulb (Just as soon as I can figure out what size I need.) If changing the bulb goes well, then I'll try to recap it just to make sure there are no further issues...

[retiredcaps]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

The first pic is the screen with a led flashlight behind it.

It's just barely noticeable though. I'll try to get a pic of it... 2 seconds isn't a lot of time though...

The flashlight test verifies that the logic board is working fine.

We really don't need a pic. We know the problem is likely either and/or

a) caps
b) inverter transformer
c) ccfl wiring

[alexanna]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

Bad idea tyring to take pictures of bright lights...(Might as well have spent the time trying to take pictures of UFOs or bigfoot... No offense to anybody who has seen either.

I believe that the CCFLs are the main issue. I will test the transformer while i have it open & attempt to replace the bad bulb (Just as soon as I can figure out what size I need.) If changing the bulb goes well, then I'll try to recap it just to make sure there are no further issues...

If one bulb is noticeably different than the rest you can plug the dim bulb into a different conector,see if the problem follows the bulb.
Do you think you will get hooked on repairing monitors like a lot of us?
If the answer is yes, when you order your ccfl get at least two extra you can use for testing, it is like buying a tool for your tool box.
Al.

[PlainBill]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

If one bulb is noticeably different than the rest you can plug the dim bulb into a different conector,see if the problem follows the bulb.

Good advice.

Do you think you will get hooked on repairing monitors like a lot of us?

Al.

I consider it the opposite of being hooked on drugs. You don't want to stop, you think you could if you wanted to, but in fact you can't. The good part: It puts money INTO your wallet.

PlainBill

[alexanna]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

PlainBill,When i was working on cars i fixed alot of them in my sleep.
Now I dream about monitors.
I know boring life but its fun.
Al.

[PlainBill]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

PlainBill,When i was working on cars i fixed alot of them in my sleep.
Now I dream about monitors.
I know boring life but its fun.
Al.

I've done the same many times, on many different projects. Sometimes the answer to a problem is slow in coming. Letting the ideas simmer for a while often leads to a good solution.

I say I have a life. It's not much of a life, but it beats the alternatives.

PlainBill

[JadeMattican]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

I switched the connectors around and the same bulb was dim/darker than the others. Thanks for the advice about buying a second bulb for testing purposes. Mostly I work on software issues. This is the most in depth repair I've ever undertaken, but I love to fix things. If it works, I'll start repairing more...

[JadeMattican]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

1. Can CCFLs Be Intermittent?

2. I no longer think the CCFLs are the issue. I'm now thinking either power, or bad wiring...

I was playing with the CCFLs again, and this time, the bulb that I determined to be bad, worked... but a different bulb was "bad." After much rearranging of the bulbs, it's now working... It remains to be seen for how long.

I stand corrected. It just shut down as I was typing, and is now back to 2 seconds to black. (Probably lasted about 2-5 mins.)

Here's another piece of odd info. There are 2 connectors at the top and 2 at the bottom for the CCFLs. The lights connected at the bottom connectors always work, regardless of which lights are plugged in...

This may not make much sense, because it's hard to explain something that doesn't make sense.

Consider this...

4 lights labeled L1, L2, L3, & L4 and 4 connectors labeled C1, C2, C3, & C4.

L1 & L2 are 1 set of lights, L3 & L4 are another. C1 & C2 are the top connectors, and C3 & C4 are the bottom.

All 4 of the lights work when connected to the bottom connectors, but if L1 is connected to C1 and is "bad" (dimmer than the rest) then it is still "bad" when changed to C2, but works fine again when connected to either C3 or C4.

The "bad" bulb could be any of the 4 when connected to the top connections, and remains the "bad" bulb regardless of it's connection to either C1 or C2.

My reasoning would be that if it were a power issue it would be one connector or another.

I'm still tinkering with the screen as I type... It's on again... L1 Is slightly dimmer on one end than the rest, but it remains on.

Hopefully this made some sort of sense to somebody.

[PlainBill]

Re: MAG Innovision LT716s 700p 2 Seconds To Black

Intermittent connection, either in the wiring to the CCFL, or the connections between the transformer and the CCFL connector, or both.

PlainBill