Question about LG Flatron F700B 17" CRT Monitor

1 Answer

LG f700b raster problem

Hello
my monitor is LG f700b.when i turn it on there are some raster lines at the top of screen that reversed to down (about 2 cm) .top of screen is blank because that lines are my monitor top screen.
about 2 hour after turning monitor on this problem decreases.

thanks for every one help

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • LG Master
  • 5,568 Answers

If the lines are slanted, you are seeing 'retrace' of the horizontal sweep. The distortion at the top is probably caused by a failing electrolytic capacitor in the vertical deflection circuit or in the power supply filtering for that circuit.
If you want to try to find this problem on your own, use great caution! There are exposed parts that can carry very nasty if not fatal voltages.
Go to any electronics parts source and buy two cans of 'freeze spray.' Expect to pay $4-5 dollars each for them. Using this on a 'live' monitor makes it still a little more hazardous since the cooled parts will form frost that may be conductive and I recommend keeping one hand behind your back so even if you touch something 'hot' you won't have currents passing through your heart.
With the rear case removed, you might drape a clean towel over the guts to let it warm up as it would if cased. When you notice the distortion going away, remove the towel and start spraying short bursts at the cylindrical parts, mostly those of 'medium' size ranging from ~ 3/4 to 1 1/2 inches in height and 1/2 to 3/4" in diameter. These are the parts with values most likely to be failing.
If you can identify the power transformer, a largish block, mostly black, check those capacitors first. You will need a mirror to watch the screen for the worsening of the distortion again and be patient; the parts you are cooling have some thermal mass so the effect is not immediate.
If you find one that seems to affect the picture, then, if you have one, direct a hair dryer (blower type) at that area to see if you can recreate the problem several times.
If you can isolate one specific part, note the value of it; it will have several printed items: - Capacitance - this will be such as this: '100 uF' - Voltage - '63V' - Polarity - this will be marked with a '+' and maybe a minus on the other leg. This is important! Any new part must be installed with the correct polarity if any is shown and it will be present on this type of part.
These parts are very inexpensive so if you cannot decide which one is at fault, replace all of them in that area; they cost from 20 cents to a buck. If you have no local electronic parts store (Radio Shack doesn't have much any more) you can order them from Mouser Electronics. Mouser has NO minimum charge and adds only real postage/shipping charges. You'll find them at mouser.com
If you decide to go this route, you will have to acquire and learn to solder with a soldering iron. Or if you have a friend who is an amateur radio operator, they will probably do this for you.
Removing the board from the bottom of the case is pretty easy, just make sure the monitor has been OFF for a while otherwise removing the thick cable from the CRT will be a really memorable experience!
Looking at the bottom of the board, note the look of the other solder joints there and do your best to duplicate them when installing the new part(s), bad solder joints can make your repair futile.
Or, you can stuff the wole thing in an envelope and send it to me ;-)
If you have been happy with this unit, it is worth the repair, since LCD monitors are often dead soon after the warranty has passed on.
Good luck

Posted on Jul 26, 2009

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Lg e700sh monitor out of shape i need the settings of original shape


try factory settings
- Press Power to turn screen off
- Press and hold Select/Auto
- Press Power to turn screen on. LED will be Orange instead of Green
- Release Select/Auto
- Press Menu
- You will see 2 additional options (Factory 1 & Factory 2)
- Exit as normal
- To return LED to Green, Power off then Power on

To reset colour:
- Choose Factory 2
- Choose Auto Color1

Jun 14, 2011 | LG Flatron F700B 17" CRT Monitor

1 Answer

Control locked how can i unlock it?


Hi,

To unlock the On Screen Display (OSD) lock, hold down the menu button for 20 seconds until OSD unlocked shows on the screen.

Please rate my answer if this helps,

Chris

Mar 03, 2011 | LG Flatron F700B 17" CRT Monitor

1 Answer

My monitor is LG FLATRON E700SH out of shape it is not getting adjusted can u please give me the perfect shape specifications


I have a problem of setting screen onto moniter ... So just suggest me what is Screen Position , Shape Size to me

Oct 08, 2010 | LG Flatron F700B 17" CRT Monitor

1 Answer

I got a black and white signal (picture ) also it is very weak , i have to increase the brightness to be able to see the black and white screen , when i turn it on some times after 5 or 10 or30 minutes it...


it usual problem with LG monitors. u can fix it just by soldering vedio board epecially vedio ic affixed on crt. bt do it gently becoz any bridging of solder may damage ur microcontroller.

Sep 07, 2010 | LG Flatron F700B 17" CRT Monitor

1 Answer

My monitor display size probs


u can adjust the screen appearance by presssing the buttons on the front...do a hit and try as i am not sure which buttons do what function in ur monitor and how they are positioned...normaly it will have function/up/down/set etc..eash option will increase, decrease, move up, move down, left, right, zoom out etc

Dec 24, 2009 | LG Flatron F700B 17" CRT Monitor

1 Answer

KDSusa Analog monitor


I would check the video card , then the connector and if the lines are still there , then you need to replace the monitor

Jul 26, 2009 | LG Flatron F700B 17" CRT Monitor

2 Answers

Audio ok, no video


I’ve never seen this kind of video output caused by a bad video cable or bad FL inverter board. it was fixed after I replaced the monitor

Apr 03, 2009 | LG Flatron F700B 17" CRT Monitor

1 Answer

LG F700B Lines at top of screen


HEY BUDY
i have same problem (exactly same!!)
see here i hope it is usefull
http://www.fixya.com/support/t2664392-lg_f700b_raster_problem
if it solve your proble please notify me

Feb 09, 2009 | LG Flatron F700B 17" CRT Monitor

1 Answer

Yellow Screen


Furst, check the video signal cable, if you can, try a replacement. Try removing and then refitting the original, sometimes this clesans the connections

Dec 26, 2008 | LG Flatron F700B 17" CRT Monitor

1 Answer

Monitor screen appears yellowish


resolder components on the CRT neck circuit! the color ICs or Transistor connections migth have loosen up!

Dec 06, 2007 | LG Flatron F700B 17" CRT Monitor

Not finding what you are looking for?
LG Flatron F700B 17" CRT Monitor Logo

348 people viewed this question

Ask a Question

Usually answered in minutes!

Top LG Computers & Internet Experts

Doctor PC
Doctor PC

Level 3 Expert

7733 Answers

Les Dickinson
Les Dickinson

Level 3 Expert

18402 Answers

Michael Vincent Cruz

Level 3 Expert

868 Answers

Are you a LG Computer and Internet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...