Forcing a monitor to stay out of sleep mode? - Page 1
Forum section: electronics / general

author: fubar.gr
author_rank: Unknown
timestamp: June 15, 2016, 02:21:17 pm
content: I have a monitor that takes 2-3 seconds to come out of sleep mode.This is enough time to miss some of the POST messages.Restarting won't help because it goes quickly back into sleep mode, but is is slow to come out of it.

author: Delta
author_rank: Super Contributor
timestamp: June 15, 2016, 03:08:45 pm
content: Maybe you would get more help if you specifiedwhatmonitor you have...

author: CJay
author_rank: Super Contributor
timestamp: June 15, 2016, 03:26:14 pm
content: Quote from: fubar.gr on June 15, 2016, 02:21:17 pmWell, you could hit the SYSRQ or Pause key and that'd hold themessages until you hit another key...And some monitors have an option to 'never standby' in their setup menu

author: suicidaleggroll
author_rank: Super Contributor
timestamp: June 15, 2016, 03:31:52 pm
content: Depends on the monitor. I have one that does that and it's incredibly annoying...it drops to sleep almost instantly when the signal is cut, and it takes so long to wake back up that you miss the entire POST, every time. You have to know what key to hit ahead of time and mash it before the monitor wakes up in order to enter the BIOS.

author: wraper
author_rank: Unknown
timestamp: June 15, 2016, 03:39:58 pm
content: There is no easy way around it.

author: mariush
author_rank: Super Contributor
timestamp: June 15, 2016, 07:18:36 pm
content: If it's that critical for you, you could use one of those active vga to hdmi or vga to dvi converters .. these have a chip inside that converts the analogue signal to a digital signal and some of these should continue to output hdmi/dvi signal even when there's no analogue signal received by the box.Of course, being a conversion from a not so great vga signal to digital, you're losing quality but hey, you get to see those 2-3 seconds of POST.My advice... just use a PS/2 keyboard (because it initializes faster than usb so it becomes responsive much sooner in the boot process) and press Pause as soon as you turn on the PC and you'll get those screens.

author: retiredcaps
author_rank: Super Contributor
timestamp: June 15, 2016, 07:55:17 pm
content: Some motherboards have a quick boot or minimal diagnostic mode. Change that to full diagnostic and it will then test all the DRAM in your system during POST. That should be enough time for your monitor to come out of sleep mode so you can see the DRAM finish testing and before the POST messages?

author: bitslice
author_rank: Frequent Contributor
timestamp: June 15, 2016, 08:53:12 pm
content: How about putting a KVM inline between the monitor and the PC?

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 16, 2016, 01:11:05 am
content: A lot of monitors dont have the ability to disable standby mode as when a monitor receives no signal on an input it after a while it will go into standby. If you plug another input into the monitor from another PC simply switch inputs when you turn on the PC.The default buttons for bios are delete, F12, F8, F10 or F2. Also Control + I is a common combo at boot to enter disk setup for some controllers. Just keep pressing them and you will find yourself in bios.Some GPUs like AMD have glitches on power saving that the GPU will hang when it enters power saving so you cant wake your PC from idle.

author: Halcyon
author_rank: Unknown
timestamp: June 16, 2016, 07:54:10 am
content: My understanding is that monitors which are Energy Star Compliant must have a sleep mode. Whether you can disable it or not; the criteria isn't clear but I'm yet to see a monitor where you can disable sleep altogether. Even my high end Dell Ultrasharp (which has more options you can poke a stick at) doesn't have such an option. You might be better off grabbing a monitor which displays the "no signal" message for a period before sleeping.Quote from: bitslice on June 15, 2016, 08:53:12 pmNo good. Even KVM's will send monitors to sleep if there is no video input from the source, unless it generates its own "no signal" graphics/overlay independent of the PC.

author: bitslice
author_rank: Frequent Contributor
timestamp: June 16, 2016, 10:20:04 am
content: Quote from: Halcyon on June 16, 2016, 07:54:10 amYeh, I was thinking of leaving it in the KVM's setup menu

author: sarepairman2
author_rank: Frequent Contributor
timestamp: June 19, 2016, 01:47:24 am
content: lol the easiest way is to cycle power to the thing.put a low frequency 99% duty cycle on a pass transistor that controls whatever PCB has the sleep function on it. You could probobly speed it up too by adding a load that switches in, to drain the board capacitance, so you dont need to wait for the decoupling etc to wait to depower the digital logic.might be enough to power down the MCU haha.

author: CJay
author_rank: Super Contributor
timestamp: June 19, 2016, 08:13:22 am
content: Quote from: bitslice on June 16, 2016, 10:20:04 amThat'd work nicely.I *think* they work by detecting HSync, I've a very overblown scheme in my mind involving an MCU monitoring the PC USB socket for power and outputting a pulsetrain on a pin or tri-stating it on power detection.Way more complicated than necessary but possibly fun to do just to prove a point.

author: amyk
author_rank: Super Contributor
timestamp: June 19, 2016, 03:25:13 pm
content: The delay is not only caused by CCFL turn-on but MCU slowness (they usually have 6502s or similar at a few MHz, and who knows what they put in the firmware...) and signal autodetection. If you try generating your own sync, it will keep it out of sleep but has to be in phase with the GPU's eventual output, otherwise it'll probably try to autodetect again."Fast power cycle" won't work, it'll either ignore the pulses because they're too fast or go through the whole MCU reset/autodetect sequence.What model of monitor is this?

author: sarepairman2
author_rank: Frequent Contributor
timestamp: June 19, 2016, 03:54:51 pm
content: Quote from: amyk on June 19, 2016, 03:25:13 pmdepends what kind of monitor you got. i got a cornea monitor that despite being old is lighting fast. they must have a ASIC in there. my nice dell monitor is a slow piece of shit in comparison.

author: Delta
author_rank: Super Contributor
timestamp: June 19, 2016, 04:01:50 pm
content: Regardless of the MCU involved, how much grunt can it possibly take to say "Yep, there's a signal, turn the power on"?

author: fubar.gr
author_rank: Unknown
timestamp: June 20, 2016, 11:03:14 pm
content: Thank you for the answers.The monitor I use is a rebranded chinese crap sold under local brand name Turbo-X. I can't find anything on their website, it is aparently discontinued. I googled the various numbers at the back label, hoping to identify the original manufacturer, but no luck.

author: wraper
author_rank: Unknown
timestamp: June 20, 2016, 11:39:02 pm
content: Quote from: sarepairman2 on June 19, 2016, 03:54:51 pmIt's fast because does not have any advanced features. My previous 30" 2560x1600 dell had 7 inputs, PIP and so on. Yep it was slow to compared with LG which had the same LCD panel. One issue, all that LG had was direct cable from single DVI connector to LCD panel and no scaler board at all, no OSD either because of this. Lag was much lower too, because no image processing at all, you know. And all it accepted was 2560x1600@60Hz or 1280X800 no other resolutions possible.

author: System Error Message
author_rank: Frequent Contributor
timestamp: June 21, 2016, 12:04:09 am
content: Just press the common buttons used to get into bios, no need to see them on the screen. Some BIOS can be set to not display the screen so you have a black screen to press keys. Its a lot easier to just press the buttons and the monitor waking up when you're in bios than it is to try to catch the press key to enter bios.