Display Collapse Recently, the top and bottom edges of the display have been fluttering and shrinking simultaneously, for several seconds and then returning to the proper position. The last several days, in addition to futtering and shrinking, the display has occasionally collapsed to a bright horizontal line in the middle of the screen. After five to ten seconds the display will revert to normal. It did this twice, right before I started this description. The screen has now been stable for at least 15 minutes. Is this a repairable condition or should I be shopping for a new monitor?
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Shine a light on the display at an angle from the side. If you can see part of what is normally displayed, then the display backlight is faulty. If the monitor is more than four years old, it probably uses fluorescent tubes in the backlight, and one of those may be going bad. The inverter detects the failure and shuts down. If you look closely, you may see a pinkish flicker on the top or bottom of the display, and more or less normal color on the opposite edge, or one edge may remain dark. That would be the bad tube. (Some monitors have four tubes, two on each edge, in which case the failed tube would only show as one edge being dimmer than the other.) I generally replace all the tubes at once; that's easier than having to go back in a few weeks later to change another one with similar wear history.
A more probable failure is a bad electrolytic capacitor in the inverter power supply circuit. (The inverter section has pink and white or blue and white pairs of wires going to the sides or corners of the display. The capacitors will be somewhere on the other side of the transformers from the lamp wires.) When these burn out, the top of the capacitor bulges up in a dome shape, and may have some leakage of the contents visible. (Note to other technicians - yes, they do burn out. I've cut them apart and found charring around the center (+) lead.) If you see bad capacitors (there may be several), replace all of the bad ones, then test the monitor.
When choosing a replacement, get one with the same capacitance (uF), the same or higher voltage rating, the same or higher maximum temperature, and make sure it will fit in the space available. Don't get one so long you can't put the cover back on over it! You also want a high ripple current rating and long life type. I usually select the Panasonic FR series capacitors. I almost never use the original brand; that's usually part of the problem. The capacitors must be installed correctly; the "-" stripe must match the position of the original part. There is usually a polarity marker on the circuit board as a reminder. A backwards capacitor will fail prematurely, sometimes with a messy explosion.
Replacement of the parts requires electronic soldering skills. The fluorescent lamps are particularly delicate; you shouldn't apply heat for more than three seconds, and you have to make the connection small enough to get the insulators back on. For that, I use 63/37 tin/lead solder; the lamps are hazardous waste anyway (mercury vapor inside).
Thin screen LCD monitor brightness controls operate several fluorescent lamps called "backlights" that are positioned behind the LCD display. Typically, they're located around the edges of the screen - sometimes just at the top and bottom, and other times at the left and right edges and others still at all 4 edges.
The lamps are miniature versions of those sold in stores. They require a support circuitry called an inverter that convert & boosts the level of DC to AC voltage performing the functions of a ballast in a traditional fluorescent fixture.
The reason a part of your screen remains dark is because one or more of the components in the picture above has failed and will not allow the lamp to shine. Replacement lamps and inverters aren't expensive - but requires patience and the ability to disassemble / assemble the monitor (which is usually harder to do than it appears) and solder. They are available various lengths and color temperatures (you must get a lamp that is identical or it will be noticed). If this is a new monitor - you ought to return it for replacement. If used, consider the cost of purchasing a replacement (new or used) vs. repair.
First place to look will be the power supply section, look for bad caps (bulging tops or bottom seals), the post back what you see so we can guide you further for direction such as voltage checking, see example of failed monitors due to bead caps: http://s807.photobucket.com/home/budm/allalbums
It can be repaired in most cases.
Your's sounds optomistic.
What needs to be done is your power-inverter board needs to be overhauled.
I do these on ebay. If
your picture wasn't pinkish or dark at the top or bottom when it was working,
then it sounds like probably the inverter was going and finally went. They are
light light bulbs and have life expectancies on the capacitors.
If your picture was pinkish or dark at the top or bottom when it was working
then you may have 1 or more of the bulbs failing.
To get to the inverter:
Once the four screws are out of the bottom edge, the the trim slides upwards to
unsnap it. You
will probably have to lift the top edge away from the screen itself as you are
sliding the trim up because it will hang up on the screens metal trim that is
unplug the screen video cable
At this point to verify possible bulb problems you can plug it in a turn it on.
bad bulbs will usually show their face here.
IF bulbs look okay then unplug the backlight bulb plugs. The
the inverter/ powerboard is under the center area under the metal cover which is screwed
Shout if you need more info.
If you email me a good picture of the inverter in the area of the larger yellow
square component, I may be able to get a better idea if it is the inverter from
a visual. Thanks