Blue horizontal lines on the monitor in the analog mode - Page 1
Forum section: electronics / repair

author: januzi
author_rank: Newbie
timestamp: May 18, 2016, 12:58:16 am
content: HiI've got a problem with my NEC1990Sxi. It started with few blue lines moving across the screen (white parts of the screen became yellow as the same time). I've thought it was something to do with the electrical grid, because it was somewhat random (like ... somebody turned washing machine or vacuum cleaner polluting across the building when firing up or something like that). I've bought digital cable (just hoping that it would fix the problem) and the problem got even worse. Now the screen turns off randomly in digital mode (DVI-D) and the lines become black and more intense in DVI-I. Well, not that randomly as I would though. When I turn Firefox on the screen looks fine until I maximize the browser. Then the screen starts to turn off and on like crazy. On the other hand, games like War Thunder or World of Tanks seems immune to that. So, I assume that has something to do with the amount of white elements displayed on the screen. When I resize Firefox starting window to quarter of the screen size and then move it around the screen works fine. The bigger the window, the bigger chances of "blackdown". At one point the screen starts to flicker and the only way to stop it is to ALT+F4.So, the question is: is it something that can be fixed by electronics noob?Help me EEVBLOG, you're my only hope.

author: EPTech
author_rank: Regular Contributor
timestamp: May 18, 2016, 07:50:30 am
content: Hi There,I suggest you try to attach the screen to another PC and check whether the fault moves with the screen.If so, the video card is probably defective.If not, try to recap the monitor's power supply. It could be the display sucks too much power out the aged power supply when it has to display a certain resolution in full screen.Good hunting.

author: januzi
author_rank: Newbie
timestamp: May 18, 2016, 11:02:25 am
content: Here's the screen photo.I've borrowed laptop and hooked it up to the monitor. The result is the same. So, capacitors are dead, right?

author: Tomorokoshi
author_rank: Super Contributor
timestamp: May 18, 2016, 11:39:35 am
content: Is the pattern influenced by wiggling the cable on either end? If it is, a couple things to try:1. Inspect the pin receptacles to see if they are spread out. This would make a weak contact.2. Clean the pins with a spray cleaner meant for electronics and connectors.

author: botcrusher
author_rank: Regular Contributor
timestamp: May 18, 2016, 11:45:38 am
content: Doubt this, sine the OP mentions that digital DVI-D is affected with the screen going on off on off, unless violently shaking somthing, i personally doubt It is a shoddy connection. Sounds more probable to me like some caps probably need to be replaced, perhaps cracking the monitor open would reveal the truth. Might not even be caps, I've seen monitors do flakey things...

author: Samogon
author_rank: Frequent Contributor
timestamp: May 18, 2016, 03:30:15 pm
content: I would definitely check electrolitics on PSU it is usually integrated into main PCB. I had to replace caps for my 5 19'' ViewSonic monitors.They were flickering, random distortions, random lines all sorts of nasty things.Once i opened them it was so obvious that i even not used any meters, just replaced leaking popped caps. And those monitors still service me well.

author: JFJ
author_rank: Regular Contributor
timestamp: May 18, 2016, 05:46:30 pm
content: Before delving inside the monitor, it might be worth trying a factory reset - from the Advanced On Screen Menu.The advanced menu is usually accessed, with the monitor initially off, by simultaneously pressing the "Power" and "Select" buttons (for a couple of seconds) and then pressing one of the OSM buttons. Use the OSM navigation buttons to locate "Factory Preset".

author: januzi
author_rank: Newbie
timestamp: May 21, 2016, 11:01:51 pm
content: Hello everybody and thanks for the answers. So, I didn't get electrocuted. The good news is that analog got fixed. Woohoo, right? Not exactly. Every single capacitor is fine. No cold solder joints either (or maybe I'm just blind and I missed it). I've put everything in the place and boom, no blue lines. Digital is still turning off and on, but with a smaller frequency.I guess I can deal with the working analog input. I'll also try factory reset. Maybe this will help?