Desktop Display Monitor
tests and diagnosis
VGA/HDMI/DVI/DP external monitor displays only. Click home for other choices like Laptop PC's.)
(test the offending monitor Other Desktops or on Laptops with VGA jacks, or HDMI to a TV) Fast checks here?
Do this or the baseline below: If the screen is dead on 2 PCs or more then the screen is now DEAD. (he's dead jim)
A Baseline dead Monitor test, and needs no working PC to do that, even disconnect the PC video cable (all kinds)
Old monitors love to fail, 2010 and older and fail the first steps above, for bad CCLF backlamps lamps.
If your new GPU card , test the base ports of the motherboard, with no GPU card inserted,
If the PC is locked up in sleep mode that is not a monitor problem at all, that is bad drivers on the PC. If you do not like sleep modes turn them off,
Relic Monitor issues.
Skipping past Cathode ray tubes all old 2000 or older displays as of 2010 all are LCD (+LED back lamped) flat screens (most are, I am skipping OELD and Plasma screens too, mostly Plasma is DOA now.)
Monitors have many types of failure modes, including failure to sleep, caused by bad cables, bad drivers in PC or using new PC on monitor older than 2007 (eDID began then)
Plug and play eDID,can fail for these reasons.
The video cables or power cable to the monitor loose or fell off, or tripped on and now broken or pins smashed, end to end.
Most monitors have 1 or 2 LEDs or just the one inside the Power button on said monitor.
Many monitors have yellow(amber) or GREEN STATUS LED here.
The amber glowing can mean the monitor is sleeping, if flashing it can mean , all inputs channels are dead. (only your monitors users manual covers the truth here)
The older monitors (2000 to 2010?) sure can go to crazy and wild self induced sleep (OSD TIMER), and tells you that if you watch the screen so turn that off that first.
One guy has a monitor with an AC/DC power LINE pack and was the wrong pack plugged in. oops. (looks like some laptop power packs or you mixed up your packs)
This monitor can fail just like laptops do to cracked screens or CCLF going bad or the inverter on the main power board failing as seen here. (the data board inside can do dead too)
Next is MONITOR Power on Tests. (long play)
Amber, = sleep mode. (usually only after 10 seconds see this or PC goes to sleep mode or hibernate mode)
White/blue/green = all mean power ok.
Black = , no AC power present ,or not turned on, or power supply inside monitor is burned out. (a bad monitor)
The Desktop external monitor powers on and will always show a logo "its OEM LOGO" , or some makers logo then "Energy Star (very common in USA) then shows errors. My desktop Shows "Viewsonic"
Now some monitor detected and presented errors: (PC on )
(The On Screen Display) OSD, Below are examples. of monitors not really dead.
What happens as the Monitor is turned on?
Well it too has a brain inide and it does self checks inside then puts up a makers logo icon (Dell , HP or Viewsonic) then scans up to 1 to 5 video input ports for live video inputs that are valid.
If it sees 2 inputs live, one is predomenent. (only your manual tells you this sceret order)
If the silly PC failed to read the eDID data , it might pick and illegal screen resolution, and will be odd locking or the monitor shows "OUT OF RANGE" (means Illegal too high resolution used)
Learn that modern monitors and same desktops can in fact change brightness on the Windows side and does to by the PC talking to the eDID chip, and can be over-ridden in the menu below.
Normally the monitor will show the PC data presentations of the booting OS or will show an error. ( if no monitor errors POP next is PC POST errors if any and last Windows errors if any.... the boot process...)
If the PC is dead, (shows NO sync the monitor can turn off) Monitors have at least 2 levels of power, ON, sleep mode or off) seen here.
The OSD menu key on the monitor face bezel always works if the PC is working right.
If the PC is dead (truly) or only lost video, the OSD runs and works about 10 seconds long, (up to 1min) and is to prevent LCD burn damage with a static, OSD menu forever. On some new monitors the OSD floats around the screen.
Each monitor has its own rules, some will not allow OSD button to work until the PC video starts working.
I can not show all (VAST) monitor screens here, but OSD screens are mostly boring and simple and near the same.
The only trick is some monitors flat refuse to OSD present if he PC is dead. Some do , Some do not. (but if the PC is dead, all monitors tell you that, "NO SIGNAL on all cables"
My Viewsonic the OSD manu, and key marked the same, is dead if the DVI cable is unplugged, but if I turn the monitor on, I get the LOGO and then NO signal , then a black screen. (this is all normal)
I am pressing the monitor bezel Menu button key, now:
OSD 1, On screen Display. PC is working 100% here.
No signal means the PC is not sending signals to the monitor , then goes to black screen.
A short history of Monitors is simple, 1987(PS/2) CRT's then 2000 year LCD +CCFL then LCD +LED (2010 year) and last OLED panels),
LCD+LED , started on the wide screens year 2010. (it took industry 7 years to start using CREE bright white, LEDs, super expensive)
CRTs ended when LCD hit the shelfs , in year 2003.( they CRTs out sold LCD for about 7 years due mostly from very high bright white LED prices $1 each, wow.)
The CCLF' short life tubes ending about year 2010. So there are 7 years of these lame old CCLF monitors(and laptops) still being used, that all turn yellow then die.
How to avoid buying junk PCs and monitors with CCFL (easy buy 2010 or newer) The HP history is here (partial)
Links to read as appropriate to your technology: (years )
Top fails: (first are old screens, with CCLF)
The dead CCFL makes the Screen black and OSD dead.
The CCFL can be dead, dim, yellow for pure white , intermittant or strobing effects (disco like) Best is to retire this junk the costs of parts and labor are 2 to 10 times what the monitor is worth.
A new screen is like $100 and used good monitor is $40 add labor and you go broke.
Monitors stand alone tests, with no PC connected, no VGA, no DVI no HTML cables attached, example HP LE2002x .
Also learn that many newer monitors not connected to a PC go in to automatic self test mode, let it and watch what it does, for sure when new to learn this and what it looks like.
You power on the monitor and it shows, this or the monitor is dead. The red words below show scanning port that shows no signal. All 100 % normal. for 2 dead or missing cables (this photo is missing cables x2)
This shows and times out, and then sleeps.(by self)
HP OSD MAIN menu, what you see after pushing the menu button.
If the PC runs you can get there via OSD menu button and crank up the brightness, some displays have dedicated buttons for just that.
Some displays have built in test pattern , nice to see if the colors are looking ok.
Old monitors have this old school malarkey, timers and what not. Turn it off and then only use the PC side for sleep mode. (if at all) Not Energy Star but Energy-DERP.
WARNING if you do the factory reset seen in main above, all this timer junk goes active, again.(pain)
This below are relic monitors, all this odd timer jive is gone now. forever. and a Pain if on.
The below should clear, that you need to turn off the stinking rotten SLEEP timer here this be first to check. 2001 to 2010 super common to see this.
I am pressing the monitor bezel Menu button key, now: This is calld OSD< for on screen display. (the monitors brain does this , never the PC)
Just turn it off. 3 click here.
If the menu button goes dead, hold menu buttion for 10 seconds and it unlocks.
On more legacy oddity is windows screen saver and you sure can turn that on, and even pick black screens , but ends at a touch of the mouse. (USB ports not in sleep mode sure)
Finding the problem and fix it : (do not read this , this is only how very old montors work, this is for the rabid curious)
Top failure modes: (the fast quick tests are here) this section here is for total screen death , no words , no text no logo's no errors are on the screen ever.
If the monitor is ok it shows logos or words but the PC is dead (you saw "no signal errors" for 3 seconded turned on) then See black screens here.
Desktop: DT monitors (when I say VGA port or cable , it means that or DVI or HDMI what ever you have connected for video to this monitor)
Steps to take for diagnosis:
The HP logo and errors seen here, (no sig) are from the Desktop monitors internal Brain. (not the PC)
Please note that monitors have there own brain (see MCU below? yes a brain processor crude) this brain will show thee status of the main video ports.
RGB = red green blue video, H = horiz. sync, V= Vertical Sync.. this old dog below uses CCLF back lamps.(600volts too or more)
Here is a list of symptoms. and tests and cures if possible.
Presentation mode at the PC END, is the best testing mode for any suspected bad monitor.
The answer to sleep modes wrong is here on one page.
This is what I do, and if this fails the drivers are bad. (even just as a simple test to force sleep OFF)
Win 10, 64bit v1903+
Dead monitors for dummies
Failure to Sleep when wanted: Just a bad GPU video jack or cable can caused this failure or using modern Monitor on very very old PC or the reverse. ( the cure are 2010 or newer monitors for all PCs)
All PCs talk (commincates) with the eDID chip in side the monitor, call it the Plug and Play identification chip (can some can set brightess too remotely)
This chip if dead (simple bad cable can do that or bent pins on the end of said cable. on both ends.) the PC can not learn what is connected at all. Impossible.
(The PC as it boots up talks to the chip and can have a eDID signaling failure)
(Applies to Sleep/ Hibernate/ Hybrid modes when I say sleep)
Some new monitors have 3 levels deep of sleep, even to say 3 watts power or less. (some PC take 15 to 30 seconds to recover from the most deep sleep modes)
Learn that many video cards go off line if any of 2 failures happen. This fools some folks in to thinking stuck in sleep mode, and is not anything to do with that.
1: The eDID is dead.
2: Any of the 3 video lines RGB , are not drawing current (means line cut) or too much current (CARD DAMAGE protections)
3: All monitors made (the monitor brain inside) even warned you "no signals , going to sleep mode now " this is just the monitor going to sleep even if the PC IS DEAD, why burn power with a dead PC says, ENERGY STAR GOD's.
DPMS modes ( wiki) this magic saved us from adding new pins.
VGA and DVI analog modes only.
As you can see if either sync line, or cable wires same or pins cut or bent,then the monitor shuts down.
In fact it will tell you going to sleep mode or only cable was unpugged. (and it for sure does not know why , only that the 1 or 2 wires went dead. (PC dead or in sleep or bad cable)
I will not ever cover digital modes, like DP or HDMI, you can learn those by googling or using the wiki first.
Power modes change by the lack of sync, and the may turn off with no sync or just text you to the screen , all input cables dead.
Each connector and its rules of usage are vastly and radically different from old analog video to full blown digital display data methods. (New PCs are DP and 4k ready end to end)
As you can see there are lots of Video or graphic sports. for 3 full decades now. (VGA is now going byebye forever) Most new PCs may have 2 ports, DP and HDMI, (HDMI for TV is still popular)
There are adapters that can just about any conversion.
JACKS so many JACKs (connectors all standard)
version 2. 12-9-2017 , 5/7/2019 (sleep mode problems)