ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes off

[quartermann]

Ok, so you guys rock. I'm glad I found this forum.

I've been attempting to follow some of the instructions on various threads here and hope that you can help me out a bit.

Those threads are as follows:
https://www.badcaps.net/forum/showthread.php?t=5965

https://www.badcaps.net/forum/showthread.php?t=14448

As the title suggests, my VA1930WM turns on and then goes off. Turn it off, turn it back on and the display goes on - then off again. Happens just as soon as the monitor realizes what input it has (analog vs digital).


I have replaced only one cap on the I/F board. It had weird funky looking pink stuff on it - thought it might have ruptured. On this picture it is part of the group of 4 caps near the top and farthest one on the right.

Like the board pictured, it is a ILIF-020 Rev. A dated "2006.06.26". (Here's the back side.)


Really nothing else looks out of sorts on either the power board or this one. Hence the reason why I'm asking what you all might think.

Thanks for the help!! And I apologize if I missed any rules.

[budm]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

How are the caps on the power supply board? I see at least 2 Voltage regulators, 3-pin with big tap on one side, they are around the top left of the pictures, please take the readings on all 3 pins.

[retiredcaps]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

2 seconds to black can be

a) bad caps
b) bad ccfls
c) bad ccfl wiring (especially the return wiring)
d) bad secondary windings on the inverter transformer

More details starting with post #19 at

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

Also, see budm's Inverter tester using old CFL

https://www.badcaps.net/forum/showthread.php?t=19987

[selldoor]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Are the pictures the actual boards out of the set with the problem - its not much good posting anything else. The pink goo may just have been the glue they use to hold components in place.

[quartermann]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

budm - I'll test those and see if we have anything coming out.

retiredcaps - Thanks for the info. Gives me more things to test!!

selldoor - Nope. I have a pretty decently trained eye for this sort of thing. Just don't know how the actual circuit works. If after trying the previous things that budm and retiredcaps mentioned, I'm still having problems, then I'll post pics of my own.

[Jasgriff]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Make sure you let us know how you get on either way.

[quartermann]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Thanks guys. So far, so good!!

Ok. After doing all the DMM tests. I'm pretty sure it's CFL related. Either that or it's driving transformer (which I think tested ok... but not sure).

I needed to test the CFL's in pairs. One pair showed 2 seconds and went blank. The other one kinda did the whole "I'm trying to get on..." but more of a "white noise" look to the screen. Just flickered - never really turned on like the other one.

With that said, I'm pretty sure that CFL is bad. Right??

I pulled it out and I don't notice anything physically out of the ordinary. Nothing is cracked. Probably bad wiring? Guessing that it's time to order another one? How would I go about doing this?

Also - just making sure it's not its transformer - it would be ok to test the "non-working" CFL on the other "working" CFL's transformer just to make sure it's not the "non-working" CFL's transformer that has the problem - right?.

[selldoor]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Yes you can test in either socket - as it is out of its case you need to be careful - best not to hold it while you try - it could be between 1000 and 4000 volts!! The wiring will be fragile so care with that do not place where it can arc to the chassis.
You can also test the good lamp in both sockets to complete the test cycle.

[quartermann]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Update: So I tested the "bad" CCFL on both transformers and left the other one in there with the screen. Switched them, tested them one at a time - both turned on on both transformers for 2 seconds.

So, unless the black marks at the ends of the CCFL lamps mean they're bad (according to budm's pics), then I guess they're ok??

Here are some pics of my two.



So... I slid them back into place and turning it on to see that both CCFL's were working together it stayed on until I finally turned it off. Upon turning it back on just to make sure it wasn't a coincidence, it started doing the 2 second thing auto turn off again.

[retiredcaps]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

So... I slid them back into place and turning it on to see that both CCFL's were working together it stayed on until I finally turned it off. Upon turning it back on just to make sure it wasn't a coincidence, it started doing the 2 second thing auto turn off again.

It sounds like loose return wiring which you cannot tell by just looking. See budm's album on burnt wiring

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

You can give the wiring a gentle tug and see if it holds or not. Here is an idea on they are put together.

http://www.ccflwarehouse.com/lasotu.html

[quartermann]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

See budm's album on burnt wiring

Right. So my question is... if the lamps have dark ends (like mine do), does that mean they're unusable? I mean... they still light up the screen for those two seconds.

Also - I'll check the joints on the lamps. Thanks for that extra link, retiredcaps.

[retiredcaps]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Right. So my question is... if the lamps have dark ends (like mine do), does that mean they're unusable? I mean... they still light up the screen for those two seconds.

Dark ends do not necessarily mean they are bad. The PWM inverter IC that is responsible for turning on the ccfls works as an all or nothing. Either all the ccfls work or none at all. When you only hookup one at a time, the expected action will be 2 seconds to black.

[budm]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

The blackened ends will still light up but it may draw too much current so the the inverter will go in to shutdown mode. Each Inverter circuits from manufacturers will have difference over current trip point, depends on how it is designed to tolerate over current situation without burning up the transformers.

[quartermann]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Hey budm and retiredcaps: So basically I should go ahead and check the wiring - resolder/fix if necessary/able. And test again if I end up doing some work.

If I don't or if that next test doesn't work - I'll probably be looking for replacement lamps?

[Jasgriff]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Quaterman,

I would definitely agree with retiredcaps and Budm here I have had this issue on a few monitors.

As retiredcaps says a gentle tug on the low voltage thinner wire will more than likely result in it coming loose.

[selldoor]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Either that or it's driving transformer (which I think tested ok... but not sure).

Well I think you need to be sure. Please measure the secondaries on the tranformers and post the results.

[quartermann]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Well I think you need to be sure. Please measure the secondaries on the tranformers and post the results.

Truth is I'm not sure if I did it correctly because I have no reference as to which pin 1 is (according to retiredcaps' thread - post #20)

So I'll include some pics of the transformer and maybe you can tell me which to measure?

There are 4 "test points" on the back of it (larger holes in the middle)... problem is there seems to be some sort of "film" blocking me access to the points on the transformer itself.

[quartermann]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

Whelp guys. Thanks for all your help. I goofed up somewhere... just made it a parts monitor. Just ordered another one.

Again, not saying you guys screwed me up anywhere. It's just that I missed a minor detail somewhere and... now I have even a more screwed up monitor as I scratched the back of the LCD. FFFFUUUUUUU.

Game over. Thanks again guys for trying to help me out. :-)

[selldoor]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

The pin numbers are on the board? I cant read them - photos are too poor.
If you need help again please post photos on site as per retirecaps post.
If you want to test the transformers test the resistance across the two pins that go to the lamps - the two at the right hand side end in your last pic. You then measure the same two pins on the other transformer and make sure they are within 3%

[StoneRhino]

Re: ViewSonic VA1930WM VS11354 - Display Turns on for 2 or 3 seconds and then goes of

My appologies if this seems like I am hijacking this thread, however, I too seem to have this issue and read through this plethora of information.

I bought a ILPI-025 Rev E off of ebay thinking this would have worked but did not.

After going back to the original Rev C board, I replaced all the caps. Oddly enough it continued the issue. A high pitched tone comes from the supply as it powers up the CFL's. After removing just one of the lamp connectors and swapping it with an external I had used with my computer case lighting, it powered up and stayed on. So it seems that one of the CFL tubes is bad.