The Screen is too dim or too bright ?  ( not bad CCFL , nor dead monitors)
In all cases the problem is hardware  bad, software bad or software set wrong.
How can discover the truth here? (by doing simple tests)
Not only that, but laptops (notepads/Tablets) are not like any desktop (true ATX spec desktops)

Page Menu:
  1. Desktop DIM (real ATX) DIM issues. (fixes and causes)?
  2. Laptops DIM (mobile PCs)?
  3. The laptop battery running PC or low the PC goes dim as seen here.
  4. Dead or UGLY LCD  screens?
  5. Dead monitors.?
  6. Examples?
  7. Use presentation mode, or the like methods, To prove out (what is the cause  of dim or black screens)
  8. Relic Monitors (2007 and older)
  9. Or those old relic Monitors with VACUUM  CRT's; really?"Cathod Ray Tubes?"


Ignoring my better judgment, I will do one page on this bit flipping topic, as it relates to SCREEN DEAD complaints.(which I cover to  the extreme)

I will not try to explain fully why sleep modes exist.  (wiki it?)
The hardware is complex in this regard, due only to the demands of USA Energy Star,  mandates,  to reduce power , when the PC is not doing useful work. "Save the planet Green stuff"
All modern PC's here go to screen blank status, after timer expires and no keyboard or mouse activity is discovered. (called sleep or hybernate mode, the latter is just deeper less power mode)
The PC can fail 2 ways, go to this mode when you don't want it to or never goes to this mode, or takes too long or too short of time to reach this state (sleep or hibenate) { it is programmable by you}
If using your PC as part of projection system for a movie theater(home?) or for a business, power point presentation, how fun is it , if the screen goes blank.?
The laptop has 2 auto dimmers modes too, for its internal screen.
The Laptop chips run the local screeen directly and can dim  the LED back lights  from even the BIOS LEVEL (even with the HDD missing)
The OS (operating system ) can set the the local DIM mode, on any Laptop or put it to sleep.
The OS can also do adaptive Brightness mode, based on ambient light in the room for go to full brightness out doors.
The laptop has DIM mode when running on battery power only. (No desktop has this)
 
Same with the age old Screen saver! if you set it to blank screen option, (yes even W10 has it, even though CRT displays are now history as is phospher burning, but some like it for fun)
Screen Saver is now hidden in W10,  click settings icon, click screen lock, the on the bottom screen saver but turn it off. (it is by default) If it was set to Blank, then bingo?  All modes this page have timer.

It will dim if you turn on "Adaptive  brightness", photo1 below.. 
This  feature uses the magic trick of using the web camera to dim the display in a dark room, or the opposite.  (or ray of light, leaking past sides or holes of  Venetian blinds? fooling the camera? )
If one uses black tape over  the camera (like mine) this feature will cause the camera to go blind, and the OS to see darkness endlessly, and go to dim brightness, set the  ADAPTIVE bit as you like,  seen in photo 1. (mine is off)
I looked in my Laptop PCs BIOS and and the configuration screen there has  check mark for 'Built in ambient light sensor"  so if you don't like this, turn it off in BIOS, this will inform the OS not to use it. (depends on OS type and versions)
My Laptop does NOT have a power loss, dim mode defeat, its not listed in BIOS at all. (so can not be defeated at this level)
If the BIOS dim works and the OS does not work as  you  want, then change it as per below screens show.
My desktop has no auto-dim modes, only the manual dim in the OSD screens of the screen brain itself.
All external screens have normal sleep modes. (more than one) (2002 or newer) the relic monitors , some HP have an internal power saver ( and early form of SPEEP).

Power settings Adjustments:
The Power ICON in the Control panel , lets you see the many modes to flip on or off or the delay.   Turn them all off.

To prove WHAT'S up with that ?, is easy by doing any/all of the following. (after turning off all those features told above)
On my 2010 Laptop the screen  aways dims when the AC power pack is disconnected , in BIOS pages even the BIOS F1 page, information DIMS or even running Freedos OS on my memory stick it DIMs.
As you can see my PC has BIOS powersaver DIM mode too, built in, that even dims with the HDD and DVD drives both removed.

  1. On old display monitors over 10 years old , they can  have a CCFL back ground lamps (not LED)   (monitor screens have vast failure modes) Yes they can do dim or even turn YELLOW.
  2. If you run below old relic HP monitor from 2002,  push the OSD button and turn off this silly reclic (now gone) POWER SAVER mode, that is only inside the actual monitor menu's. See last photo (page) below.
  3. Try another display ? Good now? Even a laptop has a VGA or HDMI jack on the rear, to connect up another screen to help solve this riddle.. (if this test passes , your other screen is failing)
  4. External screens (good) will not power dim , like in a laptop, but do go to sleep or hibernate (black screens) on commend from the PC VGA jack.

The below is checked first by the tech. or users,  if set wrong, set it as you like.
Click control panel  then click the power Icon and check each line 1 by 1 below,  and turn all that GREEN stuff off, for now , to prove this is or not the cause of your screen issues. Set it as you like.
If only windows fails, then Windows is set wrong below or currupted or infected. (if all tests fail?, it's bad hardware or BIOS set wrong, "configuration page")

Photo 1: (in the control panel big as day)  There are vast number of bits to flip here, for sure on newer and more complex PCs of any kind, what I do is turn on, Presentation mode.

Why MS insists on tiny CP screens for 25 long years,  dang... 
Here are some more there,  Photo 2:

Read each line carefully above,
ponder each one and turn them all off.  (btw: these same screens turn off other things, you may NOT LIKE,  like wifi or USB ports)!
(on my desk top all this GREEN stuff are OFF or is not available at all on any PCI VGA card, but sleep/hibernate sure is there, just no dim modes there.)
I run my desktop in presentation mode. (that old name is gone at MS,  but we can still do it, turn off Sleep and Hibernate)
If you want DIM to work, and does not , check BIOS configuration pages first....!
In most cases folks want DIM off or Sleep off or only the timer set longer. Do it now. "See it works"
 if not?, then the OS is corrupted or virus infected or the HP drivers for the screen GPU are wrong or missing. (F11 key pressed at power one , reloads the OS back to Day1, this does work, if your PC is not slammed.

 Examples:

Here is W10 , that is now stuck in  power saver mode...  on Modern Laptop. (Elitebook , HP)
 Photo 3:(running on battery only now)             (btw, running on A.C ONLY looks like this see the battery X, means missing or bad.)
HP 8540w, dimmed now. (used photoshop(tm) to make it look bright, it's not at all)
If shows 50% here,
then Windows is Dimming it, for sure.  (one can set the % anywhere one wants at any time)
 I am clicking the battery icon here, to pop up the battery status screen.
The Power controller runs in DC and AC modes.  (on battery or on AC) independently by default. The OS and BIOS do this to make the battery run longer.. (run time)

FACTOID:   (even only 1 year old , if a main battery is abused, or as we say DEEP CYCLE way too often) they fail.
Batteries love to fail, then you ignore that? and wonder why the screen dims?, it dims because the PC thinks (or may know ) the battery is bad or weak or discharging and goes to DIM mode.
The Charging chip is not GOD, It can not know or understand all ways a battery or even one cell in a battery can fail,  after all each cell or all can be, open/shorted/weak/intermittant.  So do not trust it, learn to use your backup battery first.
Only HUMANS can test a battery not some $1 chip. Sorry but that is a fact, and only YOU KNOW what run times you need , no other person nor any chip on earth knows your needs.
The book that you did not read day one told you, run times decrease every day, you use the PC,  and increases the more you over use the battery, called, excess deep cycling it. (hint keep the AC pack plugged in to the WALL)
That means it's really a battery issue, only.  (or AC power pack died)  but you can turn all that green stuff off at any time.
If the battery is old and weak, as all are, old.  The battery will have poor run time.  (use DIM mode until you get a new battery would be best)
The charge chip in the PC LT mother board can get confused if one more cells in the battery are shorted. (some even catch fire shorted)  When confused the displayed data can lie, for sure state of charge %
No lie, in this mode the battery can run 2 times longer dimmed (in some cases with a fresh new battery)
 Batteries can fail in 2 years, time or even less. (keep the AC pack plugged in and avoid most of that battery stress and the DIM issues)
The Battery lasts the longest if not cycled, keep the AC pack plugged in to reduce battery cycling (charge,discharge,charge, repeat is not good for the battery)
Store batteries fully charged.
Some PCs laptops have a battery load test or battery learn mode, it is a nice idea, but if the battery has odd problems, as many batteries just love to have , it will lie to you. (funny that, no?)
What matters ONLY is how long it runs doing real  battery mode operations, (no AC line connected) only that matters, and in most cases only a new battery passes this test, the human test, using the PC as designed on battery power.
Why wait, buy a $15 new battery, keep in 1/2 charged ,stored on  a shelf, and have it with you on vacation, because you will not find it , far from home on vacation will you? A whole whopping $15.

PRESENTATION mode is very handy for 2+ reasons,
 DLP rojectors in a home theater,  using  Kiosk modem or power point presentations to a large room of people
If any chip in the PC (vast numbers of chips) goes to sleep when you don't want that or can not suffer the results of this, then turn them all off, but there are so many bits to flip in CP Power  settings. (ugh !)
Reason #2,  Many PCs have bad drivers on many chips or just buggy and the maker of said chip flat refused to fix this !, then turn on presentation mode, forcing the PC not use that bug ridden mode. (hibernete is worse)
Reason #3 use Your TV as a screen and the PC is say running Netflix movies? Run Presentation mode.
OK here is the fix.

If all this sleep/ hibernate modes drives you mad, or you want to use  your PC with any Projection systems or use the Laptop External Video to external display and not suffer pain? (VGA/DVI or HDMI)
What can you do,? (for sure do not use the CP + Power options mode ADVANCED, to set like 20 bits there to get it like you want,  a real pain that is. CP = Control panel.
Set all sleep to off
Set all hibernate to off
Set all wake on, chips , to enabled. (for sure enable USB wake)

We can do this many ways, your actions.
  • Control panel, windows mobility center) click external display set it as you want, or need. (missing on w10 desktops)
  • On W7 up, we open the start button or go to start search , paste in "presentationsettings.exe"  As seen on my real ATX PC Desktop now, W10-64bit Pro.
  • Press Win key + P and see the settings pop up on the right and and pick "Duplicate" ,as your first test. (later try "Second screen only": works on laptops and desktops.
If  you close the lid, on any Laptop, some can not be cured of going to sleep or turns off.  (even with the power settings for that lid are set to do nothing) If you must close the lid better test this first !
This feature below works on laptops (mobile) only, and may not work on the very very cheap versions of your OS, like Windows HOME or Starter edition.)
Win+X key, type moblility in the run search box, on non portable PCs this will be missing (I have w10-64bit PRO ATX Z270p), and is MISSING on all real Desktop PCs, but present on all my laptops)



I free program that runs and turns off sleep is here. ( Virustotal.com  0 hits for safe)

A Blast from the past. (Very old Desktop Monitor) Circa years 2000 to 2007.
(the first flat panels with funky CCFL lamps inside, that go dim or yellow then die)
 
(no great fun this old beast, it's a relic of the past)  SLEEP MODE on this device is very odd how it works.
Get this fact the monitor can sleep all by it's self or from sleep commands (states) from your connected PC.
Just tune off the sleep timer (aka: power saver timer) all modern monitors are devoid of this silly features.
Warning, if you do a OSD monitor reset, the timer gets turned bad on.

 
OSD means On Screen Display, it has  tiny processor brain inside the screen now.
 The OSD has  super secret hidden deep SPEEP timer, unrelated to the PC you own, it was like version 0 EPA 'Energy STAR , malarkey.  (the reasoning was that some PCs had no sleep modes so and added it here)
Some "Odd duck" Desktop monitor displays.  See How old LCD monitors all fail with a dead CCFL seen here. (and large list of model names too and tests and more for any screens made...)


VF15,  see this?  1024 x 768 max....

OLD DOG LCD monitors, from say year 2002: (yah 15 years old)  (2000 to 2010 are the worst in LCD in the year 2010 LED BEGAN, best is to buy 2010 up)
This old dog had a   INTERNAL,  timer  clock and sleep timer,  this needs to be turned off.   (No modern LCD monitor  has this  inside it now)
Modern displays the PC side,  shuts off 1 or both cable Video Sync lines to caumonitors_and_screens/CCFL-H3LL.htmlse SLEEP, aka , advanced VESA controls.(wiki that)
Most of these displays are dead and or long gone now with the CCFL bulbs inside burned out. (mosly ended in year 2010)
 
The Oddness here is the queer SLEEP mode , that changed later with the new VESA spec standardizing sleep modes, and on that day this timer here was DELETED forever. (2007? is my guess on year change over happend)

Push the display's OSD menu button then MANAGMENT item there.,  if the DISPLAY front panel OSD button is dead?, (it's locked) push menu key for more that 10 seconds, and it unlock OSD mode.
Turn off all timers, all of them , find them all and disable them. This is CIRCA, 2000 year to 2005 (and for sure ended with LED LCD displays in 2010)
This was removed in monitors before year 2010, (approx) this timer malarkey.
  end RELIC monitors.

DIM list: #1  Laptops only
  1. The control panel device  manager, shows no errors on keyboard, mouse, USB ports nor the Video Graphics device (card or chip)  ( no red marks yellow marker , no Unknown Devices)
  2. The Brightness  set wrong on the keyboard as seen below, (yours will use different keys for Dim /bright.) The key icons are a tiny sun , is a big clue.
  3. If the laptop main battery is weak the screen goes DIM by design,  remove the battery, if the screen goes bright, BINGO ! leave it out that battery run on AC only)
  4. The PCs ambient light detector feature is turned on, it will go dim in a dark room,  aka: Adaptive Brightness feature, turn it off if you don't like it.
  5. All old CCFL go DIM. (really are not all dim?, 20,000 hours usage.  10 Hours used per day for 5.5  years,  bingo you are there DIM BULB CITY or yellow /dead or intemittant CCFL tubes.
  6. The LCD backlamp  inverter card, has problems. (rare! above line is 10x more likely)
  7. The screen goes black in sleep /hibernate mode, so is not really DIM, but turn off sleep if you  do not like it turn it off in CP + POWER settings.
  8. If the screen  is cracked or full of colored lines the LCD panel is bad, or cable to it  or the chip driving this LCD is bad.
This tells me (shouts) someone does not know how to load the OS fresh , using wrong install media and wrong drivers.
The cure above, is get your drivers, from your PC maker. (if MS plug and play fails as sure did above)  By OS version and by PC model exactly, best is ask you OEM for the correct drivers. The above person did not.
The #1 reason for above, is upgrading the OS, not asking the maker first, if you can. (case in point W10 does not support most old  device functional chips)

No 2 laptops use the same keyboard nor same the drivers, nor same keys for DIM.  This PC we push blue Fn + arror up  or down.
For the above keys  to work the correctlyt he  OEM driver must be installed , matching your PCs model exactly and OS version. (or it WILL NOT WORK) (the exceptions and advanced methods are here)
All laptops made dim the screen on battery mode, or if  the battery is weak or battery defective. (even with batteries with shorted internal cells)
All do this DIM until you buy a new battery and use that, or run on AC pack only even with battery removed, forever)

Dim list #2 Desktops Only:   ATX Desktops , not Fake ones called "All_In_One Desktops" that I avoid and never cover.
First off Desktops have no internal screen nor any kind of laptop main power battery.
The desktop uses only an External monitor. (best are LED LCD back lamped monitors) "I like ViewSonic and HP Monitors (and DELL)"
Hard failures are covered here extensively.

List:
  1. The monitor fails on 2 PCs or more the monitor/ cable is bad, or it was made (built) 2000 to 2007  and has its own OSD timer (power saver timer) turned on, so turn it off.
  2. The monitor, also warns you  if the PC goes dead /sleep or hibernate, with lots of errors," cable disconnected, no Signal, no Sync, out of range, or Going to Sleep mode and goes black)  This is PC problems not monitor.
  3. A bad cable.  If the video Sync lines fail, the monitor goes black with errors above.
  4. The monitor is in fact dead if the OSD screens never work with the pressing of the monitor menu button,( with-in 5 seconds of monitor turn on) if the power lamp on the monitor is dead, the monitor is dead.
  5. The Desktop PC can not really DIM any monitor, but can set it to black screen ,(black is not DIM) Black screen is sleep or hibernate modes.
  6. All monitors have there  own brightness buttons on the front panel or hidden in the OSD menu. The monitors users manual covers all this, why not read  it,  google like this, (monitor make/model# manual)
  7. The old monitors made from year 2000 to 2010 had CCFL back lamps and all of them now are 8 year old or older and all are now dim, never seen one ever now, not DIM. (unless parked on shelf for 10 years)
  8. The monitor power lamp may have 3 modes (color LED lamp) Green power on normal, and Amber, in sleep mode.(see this link on all monitor failures vast and lots of testing)
  9. The PC software can make the monitor go black not dim, the monitor will show error "out of range" so at the PC set the video resolution to your old monitors poor resolution, even 800x600.
  10. If you suspect the above, Out Range, use windows safe mode F8, (800x600)  Most monitors made can do at least 1024x768. (read your monitors spec, learn where MAX is?  the set it to max"or stated as BEST")
Offline testing monitor: VGA/DVI/HDMI cable not connected:
The OSD on all monitors do not run 24/7 up on screen, if they allowed that the screen LCD will burn.
The OSD menu times out in 5 to 60 seconds, most monitors you can change the OSD time out delay to 60 seconds,  for more easy testing off line.
Power on , and quickly push MENU, if OSD looks bad or is dead the monitor is NO GOOD. (turn up the brightness in the OSD now or down if that is your need)
ONLINE:
If the PC is connected and PC running now, next and not sleeping the OSD menu will work 24/7 that is will not time out, in most cases.
If not sure how this works find a good monitor and play with the OSD, learn how it acts. (OSD time out is really the only trick here)
 


end saga.



version 1.  5-9-2017,,By: Deadpool