# Monitors show "No Signal," Why? **URL:** \ **Category:** Factual Questions\ **Created:** [June 8, 2007, 2:49am UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215 "2007-06-08T02:49:58Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Epimetheus](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@Epimetheus](https://boards.straightdope.com/u/Epimetheus)\ **Post date:** [June 8, 2007, 2:49am UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/1 "2007-06-08T02:49:58Z")
I think it might be a virus, because my girlfriend’s computer started doing it the same day mine did. I leave my computer alone for awhile, come back and my computer has the light on, but there are no HDD, fan or other sounds coming from it, and my monitors say “No signal” as if my computer is off. I have to turn off the computer and turn it back on. Is there a new or old virus that does this? I double checked all my settings, in the BIOS and in Windows (Windows XP Pro), and there is no sort of hibernation set. Neither me nor my GF have changed anything recently to cause this, and they both started doing it exactly the same day. ---
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [June 8, 2007, 2:56am UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/2 "2007-06-08T02:56:31Z")
Does she live with you? If so, it is probably a power problem at your place. That will cause that and happens to me occasionally at home. Another possibility is heat/ Did you do anything like construction that would kick up a lot of dust and get sucked into the computers? That happened to me one time as well. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [June 8, 2007, 2:58am UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/3 "2007-06-08T02:58:19Z")
No, that’s your monitor doing that internally; your computer is off an dis not sending a video signal. It’s simply letting you know that your monitor is, in fact, working and is capable of displaying graphics. If it were a blank screen, as many older monitors would display, you might not be sure whether it was the monitor or the computer which was the problem. ---
**Author:** ![Epimetheus](https://avatars.discourse-cdn.com/v4/letter/e/c4cdca/32.png) [@Epimetheus](https://boards.straightdope.com/u/Epimetheus)\ **Post date:** [June 8, 2007, 3:00am UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/4 "2007-06-08T03:00:13Z")
We live apart. In fact, she lives in Jefferson City, mo and I live in Columbia, mo, so we are separated by around 30 miles. I talked to her just now and she said she has not had it happen to her except for that one time. It might be a power thing, but I have a surge protector though not a UPS. Perhaps I should invest in one. I have moved recently though, and it never happened at the other place, so you are probably on to something. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [June 8, 2007, 3:08am UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/5 "2007-06-08T03:08:35Z")
I kinda misread the question. It could be a trojan; some variant of the old Blaster worm. It’ll generally cause an NT AUTHORITY SYSTEM shutdown because it messes with some critical system service. You’ll get a popup announcing the shutdown and timer counting down from 60 seconds. Any current virus scanner, including the free AVG Antivirus, should detect and eradicate it. ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [June 8, 2007, 12:20pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/6 "2007-06-08T12:20:22Z")
Check your power management settings, too. Your PC could be dropping in to standby and turning off the video output. Tapping the space bar **should** wake up the pc, but this is not guaranteed. Si ---
**Author:** ![Merijeek](https://avatars.discourse-cdn.com/v4/letter/m/f05b48/32.png) [@Merijeek](https://boards.straightdope.com/u/Merijeek)\ **Post date:** [June 8, 2007, 12:32pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/7 "2007-06-08T12:32:30Z")
[QUOTE=si\_blakely] Check your power management settings, too. Your PC could be dropping in to standby and turning off the video output. Tapping the space bar **should** wake up the pc, but this is not guaranteed. [/QUOTE] I second this one - it’s most likely going into a powersave and not coming back out correctly - because Windows blows. Go to Control Panel-\>Power Settings and set all those drop boxes to “never”. -Joe ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [June 8, 2007, 12:34pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/8 "2007-06-08T12:34:48Z")
I see this occasionally on a setup I have with 2 PCs connected via KVM switch to one monitor. If they’ve both been sitting long enough that they would have gone past their “screen saver” phase to their “let the monitor go to sleep” phase and I switch from one to the other, the monitor will display “No signal.” Basically, it’s telling me, “Hey, all of the sudden, there’s nothing feeding me. What’s up?” ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [June 8, 2007, 12:38pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/9 "2007-06-08T12:38:15Z")
[QUOTE=Merijeek] I second this one - it’s most likely going into a powersave and not coming back out correctly - because Windows blows. [/QUOTE] Spoken like a man who has never tried to get hibernate and suspend working on a laptop running Linux. I am batting about 75% successful hibernate/restores in Kubuntu. :rolleyes: Si ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [June 9, 2007, 4:09pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/10 "2007-06-09T16:09:20Z")
[QUOTE=Merijeek] because Windows blows-Joe [/QUOTE] FWIW, one of the 2 PCs I mentioned above runs Ubuntu, and it works the same either way. Not that my situation is necessarily what the OP is getting, but still. ---
**Author:** ![Rysto](https://avatars.discourse-cdn.com/v4/letter/r/ecccb3/32.png) [@Rysto](https://boards.straightdope.com/u/Rysto)\ **Post date:** [June 9, 2007, 5:17pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/11 "2007-06-09T17:17:12Z")
[QUOTE=si\_blakely] Spoken like a man who has never tried to get hibernate and suspend working on a laptop running Linux. I am batting about 75% successful hibernate/restores in Kubuntu. :rolleyes: Si [/QUOTE] I’ll take crappy ACPI implementations for $100, Alex. ---
**Author:** ![ChrisBooth12](https://avatars.discourse-cdn.com/v4/letter/c/e95f7d/32.png) [@ChrisBooth12](https://boards.straightdope.com/u/ChrisBooth12)\ **Post date:** [June 9, 2007, 11:23pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/12 "2007-06-09T23:23:42Z")
Its probably either set to digital or analog, have her press a + button on the monitor or a 1 or 2 and change it to the correct setting, the CPU might also be in standby mode ---
**Author:** ![KlondikeGeoff](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@KlondikeGeoff](https://boards.straightdope.com/u/KlondikeGeoff)\ **Post date:** [June 10, 2007, 1:20am UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/13 "2007-06-10T01:20:49Z")
[QUOTE=si\_blakely] Check your power management settings, too. Your PC could be dropping in to standby and turning off the video output. Tapping the space bar **should** wake up the pc, but this is not guaranteed. Si [/QUOTE] A definite possibility. Did you notice, when this happens, whether the ON light on your box is blinking? If so, and even if not, next time try hitting the ON button on the box and see if that starts everything. If so, you were in standby mode. ---
**Author:** ![Merijeek](https://avatars.discourse-cdn.com/v4/letter/m/f05b48/32.png) [@Merijeek](https://boards.straightdope.com/u/Merijeek)\ **Post date:** [June 10, 2007, 1:48pm UTC](https://boards.straightdope.com/t/monitors-show-no-signal-why/407215/14 "2007-06-10T13:48:03Z")
[QUOTE=KlondikeGeoff] A definite possibility. Did you notice, when this happens, whether the ON light on your box is blinking? If so, and even if not, next time try hitting the ON button on the box and see if that starts everything. If so, you were in standby mode. [/QUOTE] For that matter, what color is the power light on your LCD at that time? -Joe