Question about ViewSonic VX910 19" LCD Monitor

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Viewsonic VX910 CCFLamp drivers...

Hi, I found 2 of my CCFL drivers shorted Q6 & Q7, problem is they are SMD transistors, and they only have 4 letters written on top DK QA. I replaced them with a DK QM I had, it worked for about 24 hours but looks to me they went bad again, I can't find how to read this letters(manufacturer code), on the other hand I think the transformer is probaly shorted too. Where can I find any information on this board, a schematic or a clue on the name of this 2 transistors? Thanks Io.

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Re: Viewsonic VX910 CCFLamp drivers...

One and a half year later I know the solution :-). It is 2SC4672... sure!. DKQ* is in my Jaeger SMD-Decoder book (10.000 SMD - Demiconductor - Codes)
Common problem with inverter PCB. Caused by the damaged or loose 100nF (or some same value)
Succes. For me it is working.


Posted on Feb 27, 2009

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Re: Viewsonic VX910 CCFLamp drivers...

This is not a solution but I am just surprised that you have the EXACT same fault as me. I've done some searching on datasheetcatalog website and apparently the letters DK mean it is a BCX42 PNP Silicon AF and Switching Transistor (For general AF applications High breakdown voltage) however the datasheet for this device is a 3 pin smd not a 4 pin so I'm not sure that it is correct.

Posted on Sep 17, 2007

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Lost my driver software how can i get a copy off the web?

You don't need drivers for moniters because they are automatically installed when plugged into your pc. If you are looking for any software it may have come with, then you can download it for free from Viewsonics website/support section.

Feb 28, 2011 | ViewSonic VX910 19" LCD Monitor

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My screen goes on and shuts right off

I will assume that you have already try it with other PC and get the same result. Coomon problem are bad caps in the power supply, but you can also have bad inverter circuits (shorted transistors, transformers), bad lamps. You will need to open it up and inspect the inside.
See pictures of failed VIEWSONIC here for guide:
Post back what you find so we can guide you further and help out other people as well.

Apr 05, 2010 | ViewSonic VX910 19" LCD Monitor

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My monitor will display the picture for approx 1-2 seconds, then the word "analog" is seen and immediately the picture disappears. Bottom line: the picture won't stay on.

I assume that you have already try this monitor with new VGA cable and with another PC but still get the same result, just want to narrow down the problem before opening it up.
Most common failure in the LCD monitors are bad capacitors (bulging top/seal or leaking) in the power supply, failed inverter circuits (blown fuse, shorted transistors, shorted/open transformers), bad lamps (poor solder connections or worn out lamps). You will need to open it up and inspect the inside, see example of failed VIEWSONIC nad other monitors to get some ideas what goes wrong:
Post back what you see inside so we can guide you further.

Apr 02, 2010 | ViewSonic VX910 19" LCD Monitor

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Monitor turns black after 2 seconds, Viewsonic VX910

Check the power supply first for bad caps, then check to see if you do have 12vdc feeding the the inverter circuits, worst case will be the lamps, see example of failed VIEWSONIC monitors due to bad caps:

Jan 21, 2010 | ViewSonic VX910 19" LCD Monitor

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I have a viewsonic VX910 and the picture goes off and on. Picture lasts less than a second. I replaced the 3 caps but no good. I measured some power points on the PSU and see the drop, even the A/C drops...


This could be caused by a few things. First, be sure the capacitors you used are low ESR. You can't use capacitors from Radio Shack, they can damage the electronics. Second, on the bottom of the power supply board you will find 4 transistors, they may be blown out. Check them with a multimeter or transistor checker. If the transistors are blown, we carry them is stock if you need them.
Contact us at: if you need any additional help.

I hope this helps, if so please rate our solution.

Corporate Computer

Jan 02, 2010 | ViewSonic VX910 19" LCD Monitor

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Viewsonic vx924 power/inverter board

See ebay item 390074135923

Jul 23, 2009 | ViewSonic VX924 19" LCD Monitor

1 Answer

ViewSonic VX910 monitor has a power supply issue.

Your monitor have a bad condensator in the PSU.

The only thing to do is to replace the Power Supply Unit (very expensive, more than a new monitor) or if you have electronic tools, found and replace that condensator.(cheaper way...)


Have you connected your monitor with a new power cord ?

Best Regards!

Jun 29, 2009 | ViewSonic VX910 19" LCD Monitor

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ViewSonic VX924 transistor

Hey Brandon.
Besides those transistors, you may also fine the large capacitor adjacent to the transformer gone too, Possibly the transformer may be bad too ?
Also the 924s used at least two style boards.

Jun 17, 2008 | ViewSonic VX924 19" LCD Monitor

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Help in identifying this transistor for my VX924

Are they black with 3 SMD pads? They should have a tiny tiny number on the top corresponding to a SMD code that will tell you what they are (example: D9A means 5.5V zener diode).

You should be able to just get a new inverter or repurpose an inverter out of something else to get it working again. An inverter that powers any other CCFL bulb should work fine.

Mar 16, 2008 | ViewSonic VX924 19" LCD Monitor

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LCD monitor problems.


If the monitors use seperate plug in power supply EG 12 to 24volts it could be that at fault.
Or it could be the invertor at fault.
I have had some success repairing invertors if you can use A meter remove invertor Panels & check accross the coils with meter set to ohms all the coils should read identical chances are you will find one set of windings either dead short or open circuit. This will be the faulty coil hopefully as your monitors are all the same make the coils will be the same.
Carefully desolder faulty coil & fit one that reads good from a doner board.
Look for any SMD type fuses & check or replace them & thats it I have done quite a few now using this method.
Give it a go.


Dec 30, 2007 | ViewSonic VX910 19" LCD Monitor

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