Hi , I have got viewsonic 19 " LCD Monitor VA1918wm-2. When it starts up the backlight flashes , some sort of hissing sound and shuts down. Verified No picture under bright light. Replaced 4 Capacitors, but did not help. If only one ccfl is connected flashing stops.
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Viewsonic 19" Flashing backlight and no display.
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Re: Viewsonic 19" Flashing backlight and no display.
'Hissing', can regularly be related to a wiring fault on Backlights,or less likely a dry joint somewhere on the Board.Would try some test backlights in place of the original first, and see if that corrects things before you start opening the Screen to check.
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Re: Viewsonic 19" Flashing backlight and no display.
There is some scorching showing on the board - can we have a picture of the back.
If it is not a bulb problem then I would change all the caps except the BIG one
with Good Quality low ESR caps - panasonic or nichicon if you can get them.
If you have no spares lamps to test with see this:
https://www.badcaps.net/forum/showth...ght=test+lampsPlease upload pictures using attachment function when ask for help on the repair
http://www.badcaps.net/forum/showthread.php?t=39740
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Re: Viewsonic 19" Flashing backlight and no display.
Hi, I'm having a similar problem, actually it's exactly the same except that there IS (barely) visible picture under bright light. I've checked both power and input boards and no visible damage, for me that is. I can't post pictures today but I'll try to do so tomorrow.
@OP, did you end up fixing your problem?
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Re: Viewsonic 19" Flashing backlight and no display.
Hissing from top corner sounds to me like arcing from high voltage, this can be due to bad wire connection at the end of the lamp.
See example here:
http://s807.photobucket.com/user/bud...?sort=3&page=1
Do you smell any ozone?Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Viewsonic 19" Flashing backlight and no display.
Not really, I don't. Here's what happens a bit more detailed:
If I leave the screen off for a few minutes/hours, when I turn it on, it works perfectly fine. After one or two minutes, the hissing/buzzing begins, along with the backlight flashing. This gets more intense over a few minutes, until it finally stops for like a second or two, and then the backlight goes off. If I power it off and back on it will start buzzing and flashing immediatly and goes off after like 2 or 3 seconds.
Would this happen from a bad connection? Shouldn't it start happening right away instead of only happening when the screen gets warm? I don't know, just asking
And if it is indeed my best bet, how can I get to the CCFLs to see it?
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Re: Viewsonic 19" Flashing backlight and no display.
When you have bad connection, when it gets warmer, the connection gets worst due to higher contact resistance.
Getting to the lamps is not easy, you will have to disassemble the panel to get to the lamps.
You use test lamps to verify if it is the board problem or the lamps problem.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Viewsonic 19" Flashing backlight and no display.
Ill try to get them tomorrow or so then. One thing: the screen has two pairs of blue/pink cables, the ones for the backlight; if I disconnect one of them, the backlights dont flash BUT are only lit for about 2 seconds after I turn the screen on. Is this relevant?
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Re: Viewsonic 19" Flashing backlight and no display.
Originally posted by brgil96 View PostIll try to get them tomorrow or so then. One thing: the screen has two pairs of blue/pink cables, the ones for the backlight; if I disconnect one of them, the backlights dont flash BUT are only lit for about 2 seconds after I turn the screen on. Is this relevant?
What I do is.......get a set of test lamps. Unplug 1 set of lamps. Plug in the test lamps. See if it stays lit. If it goes out, move to the next plug. Once you get to the bad set of lamps it will stay lit with the test lamps plugged in. That's your bad set.
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Re: Viewsonic 19" Flashing backlight and no display.
Make two of these:
https://www.badcaps.net/forum/showthread.php?t=19987Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: Viewsonic 19" Flashing backlight and no display.
aha - new store name!!!
linky!
http://stores.ebay.com/lcd-led-parts...p2047675.l2563
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