Viewsonic VA912

[matthmal]

Hi guys,

I have this viewsonic VA912 monitor with external power adapter. The problem is 2 seconds to black.

I was thinking whether I can bridge the inverter part of the board to a universal inverter board. Usually when I do this I solder the cables of the inverter board with the cables going from the power board to the video board but this board is different. It doesn't have any cables but it has metal connectors.

Can someone help me to understand which of the metal connectors are ON/OFF, ADJ, GROUND, and a voltage of +10V or more?

Thanks,
Matt

[matthmal]

Re: Viewsonic VA912

anyone please?

[LaGGER]

Re: Viewsonic VA912

IDK does someone read this post but if someone can help me I fixed problem with lg flatron w1932S but after 1 year it goes black again and when I (monitor was in service centre where was fixed) open the case I found this(will be attached) and now I can't find the components and I dont know does this(its circled on image) is in good condition(IDK translate to english I'm from Macedonia)so if someone can help me the exploded capacitor is 27pF 3KV there are 2(1 is exploded) http://prntscr.com/1zhioa

[budm]

Re: Viewsonic VA912

What is the model VS number?

[matthmal]

Re: Viewsonic VA712

What is the model VS number?

What do you mean by VS Number?

Sorry by I had a mistake guys.

The model number is VA712 and I turned it on again and found out that it has no power.

It has an external power supply which is 19V and 3.16A. I tested it with my meter and it showed 19V.

Please find attached photos of the monitor.

[budm]

Re: Viewsonic VA912

There are more than one version of this model (Viewsonic always makes more than one version of the same model number). You can see the other model number on the tag. I am trying to see if I have the service manual for your version. Most of the VA912 I repair have built-in power supply.
For example of the tag:
http://s807.photobucket.com/user/bud...tml?sort=3&o=0

http://s807.photobucket.com/user/bud...?sort=3&page=1

[matthmal]

Re: Viewsonic VA912

There are more than one version of this model (Viewsonic always makes more than one version of the same model number). You can see the other model number on the tag. I am trying to see if I have the service manual for your version. Most of the VA912 I repair have built-in power supply.
For example of the tag:
http://s807.photobucket.com/user/bud...tml?sort=3&o=0

http://s807.photobucket.com/user/bud...?sort=3&page=1

Please find attached the tags of my Viewsonic for your perusal.

[matthmal]

Re: Viewsonic VA912

Any help is much appreciated please. Thanks guys

[budm]

Re: Viewsonic VA912

Sorry, I cannot find the SCH for your version of the boards you have.

[matthmal]

Re: Viewsonic VA912

So there is nothing that can be done to this set? Cause if so, I will just throw it away and make some more space.

Thanks a lot.

[killian6pk]

Re: Viewsonic VA712

What do you mean by VS Number?

Sorry by I had a mistake guys.

The model number is VA712 and I turned it on again and found out that it has no power.

It has an external power supply which is 19V and 3.16A. I tested it with my meter and it showed 19V.

Please find attached photos of the monitor.

In your second picture you can see U10 and U9 on the board these are labled on the part as 1117, Bud has a section at the bottom of his reply to you about how to test these(LDO Testing). It sounds like your power supply is ok. These little regulators go out often on many models of monitors and tv's. Also check to see if there are others, I think there are at least two shown in your 3rd picture. I did not look the boards over very closely. Also look for SMD fuses on all of the boards. They will have a board designation of F??? and will usually be white. There may be at least one of those on each board. Test them with your meter set on ohms and should read less than 1 ohm. I see at least one SMD fuse in your 3rd picture next to where the two boards are joined at the connector. Hope this helps.

[budm]

Re: Viewsonic VA912

OK, this chassis VS10697 seems to match yours, see if they are closely match your boards.

[John Hopf]

Re: Viewsonic VA912

I have a VA912b that is doing the 2 seconds on and off thing.
It did have a few bulging caps and I replaced all 7 of the E Caps there.
But it is still acting the same.
The two fuses are OK. I don't see any others on the 2 boards.

Any help? How can I check the 2 tiny voltage regulators?

[selldoor]

Re: Viewsonic VA912

John
If you board is the same as Matthmalls first picture you can see the two inverter transformers. With no power to the board, set you meter on ohms 2000 and test
across from the two pins to the single pin on each and post the results.

Read this by retiredcaps- there are lots of tests- start at post 19
https://www.badcaps.net/forum/showthread.php?t=10419

[John Hopf]

Re: Viewsonic VA912

Mine is different. It only has one transformer.

[selldoor]

Re: Viewsonic VA912

Mine is different. It only has one transformer.

Well ok but thats not much help - picture of it? board number?

[John Hopf]

Re: Viewsonic VA912

I see it here - http://lcdparts.net/TransformerDetai...ProductID=2724
Mine measures 0.5 ohm primary and 999.0 ohms secondary on one side and 0.5 and OPEN on the other. So I guess it is bad. Where is a good place to get a new one? From that link?

[budm]

Re: Viewsonic VA912

Like this?
http://s807.photobucket.com/user/bud...?sort=3&page=1

[John Hopf]

Re: Viewsonic VA912

This is it http://www.ebay.com/itm/100-New-Inve...item4d072f946b

[John Hopf]

Re: Viewsonic VA912

Yes, that is the one I have. Thanks for the link !