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CRT Monitor: Screen goes black with bright horizontal line in center
Happens randomly, on / off fixes it for a little while

 8:59 pm on Feb 25, 2008 (gmt 0)

Has anyone dealt with this before. I have a LaCie Electron Blue CRT monitor. It's about 4 years old. I love it. We are best friends. But, lately it has been acting funny. I will be working on any number of things and randomly the screen will go all black except for a thin bright (white) horizontal line right in the middle of the screen. Sometimes, but not always, this is preceded by the top and bottom of my display "flickering" or contracting. Turning the monitor on and off usually works, but sometimes I have to do it many times to get the display back. I have cleaned the back out with canned air and that did nothing.

Has anyone dealt with this sort of thing before? Maybe with another brand? This monitor is way off warranty so I am wondering if a repair shop could fix it without costing me an arm and a leg.

I love my Electron Blue! Does anyone know what is happening? :(



 12:53 am on Feb 26, 2008 (gmt 0)

The circuitry that controls the vertical displacement of the electron beam in knackered. You can probably buy a new flat-panel monitor for less than it would cost to fix (even though it is no more complicated than switching a board).

The typical life expectancy of CRT monitors is about 5 years depending on usage, so even if you get it fixed, it probably won't last that much longer.

If you have a friend who knows his way around analog circuit boards, he might be able to fix it if it's nothing worse than a bad solder joint.



 1:18 am on Feb 26, 2008 (gmt 0)

I was soooo afraid you were going to say that! Alas, thank you for your reply.


 3:33 am on Feb 26, 2008 (gmt 0)

If you're feeling brave...

Disconnect it from everything (computer and mains) and leave for one hour (to ensure high voltage components discharge). Remove the cover then unplug and replug all the easy-to-reach connectors. Pay particular attention to connectors at the back of the tube.

Even after an hour, some monitors may still have highly charged capacitors, so wearing rubber gloves is certainly worth considering if you don't know what to look out for. Also, some connectors may be delicate and may require careful inspection to determine how to remove them so be thoughtful and gentle.



 2:58 pm on Feb 26, 2008 (gmt 0)

You have a fault called intermittent frame collapse.

If tapping the casing causes the fault to appear or disappear its probably a bad connection - where the scan coils join the main pcb or dry solder joints.

Take it to a tv repair shop, do not attempt to repair it yourself CRTs use very high voltages (tens of thousands of volts) your monitors power supply smoothing capacitor works at around 400V both can hold their charge for several days.

Please pay an expert to do the job safely, if it only requires soldering it shouldn't cost too much!


 4:29 am on Feb 27, 2008 (gmt 0)

If you *are* going to go inside, use only one hand and keep the other one in your pocket. Try to find the tv repair faq on the net it is very good.


 9:10 am on Feb 27, 2008 (gmt 0)

use only one hand and keep the other one in your pocket

Good advice, the idea of this is to stop the voltage going across your heart (from arm to arm), but it won't stop you getting a nasty shock.

Repair shops use a resistor with heavily insulated leads to discharge capacitors and the line output transformer before starting work.


 4:27 pm on Feb 27, 2008 (gmt 0)

Thank you all for your input. The whole "make sure the current doesn't pass over your heart" has scarred be witless. I'm not going to touch it.

I think I will take it to a shop for an estimate and see if its worth the repair.

Thanks to everyone. It helpful to be able to ask these questions.


 6:50 pm on Feb 27, 2008 (gmt 0)

There are a couple of these monitors on ebay at the moment.


 8:39 pm on Feb 27, 2008 (gmt 0)

Ebay... very interesting. Thanks for the heads up!


 8:51 pm on Feb 27, 2008 (gmt 0)

I used to work at Samsung making CRT monitors. There is a cable with exceptionally high voltages on the back - one lad went to touch this while the monitor was on and he bounced off the next production line (about 10 metres away) and couldn't use his arm for almost 6 weeks.

And note, he didn't actually touch it - he was a couple of inches away!

They are not to be messed with unless you really know what you are doing.


 4:30 pm on Apr 13, 2008 (gmt 0)

Arrived here via google search having exactly the same problem with my Blue Lacie IX monitor, and am very impressed by quality replies given out here.

Seeing so many experts' replies here, I feel like to ask what is a comparable monitor to my Blue Lacie IX 19", should I decide to get a new one?

I am a pro photographer and need a good quality monitor to show my clients picture like images on monitor...

[edited by: tedster at 4:18 am (utc) on April 14, 2008]
[edit reason] no email addresses in posts [/edit]

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