Monitors , Displays and Screens , problems (solving them)   

See how , Sleep mode or hibernate mode or screen savers can fool you, see why and the cure , here.

There are many screens,  used for ages,  CRT (cathode ray tubes; Legacy),  Desktop LCD then, LED , and LCDs inside Laptops (notebooks) both CCFL or LED back lighted.
Index: (failures)
Desktop LCD
Laptop screens
Solder balls from H3LL
The Flash light test.
Inverter  or   CCFL fails
Desktop Inverter

DISPLAY's & Monitors & Screens 101: (do not read this history / facts jump to fixing it now)
Skipping past Cathode ray tubes all displays now are LCD flat screens (most are, I am skipping OELD and Plasma screens)
PC turned off:
The Desktop external monitor powers on and will always show a logo "HP" ,  or some makers logo then "Energy Star (may show up) then shows errors.
  • "NO SYNC" errors.  means the horz/vertical sync lines in the cable are dead. (PC issues)
  • "NO signal" means  1or both Video lines in cable are dead. (PC issues)
  • "No connection" errors means all lines are dead, in the cable. (PC video dead)
Then promptly goes black.  (you can repeat this over and over (power on, see logo, see Signal then it goes black screen)
The OSD menu button goes dead with no sync.  (this may be to protect the screen for static damage if the OSD was left glowing endlessly.)
(the On Screen Display)
The fact is you must have 2 live sync signals for the video chip to even select a valid resolution for the OSD or all you get is a fleeting LOGO "like HP  or Viewsonic, then and error message above then black screen)
With the PC turned on, and the menu button pushed, an OSD screen shows up. Like this. If not it shows No Signal, even if pull the VGA or DVI cable on a good running PC and screen.
If the screen shows, the logo and No signal, in most cases the Desktop LCD display is good. (with a dead PC only the HP logo (or your makers screen ) and No signal show up for only about 3 seconds.
The best way to test this screen it try it on aother PC. (desktop or laptop) with VGA jack tests.
If the PC goes to sleep, the screen will tell you that just before it goes black screen.
Then the new VESA standards added PC commanded sleep modes. (and is related to PnP, plug and play, the OS must know what display is there or it can not set the correct resolution mode.
Odd duck old screens (circ 2002 year)  See more here...
The very old screens (external) had a sleep timer inside , near year 2000 and after 2004 all had sleep modes now located in the PC and the DISPLAY SLEEP timer (Desktop)was deleted.
The sure is easy, push the display front panel menu button and turn off the SPEEP/Power saver timer now.
The Grapics video card or chip (and friends) could force sleep now, simply by disabling  either of the 2 SYNC lines to the Display,  (they changed the rules 4 times, to make all this fun) (not)
The screen errors are all true and real,  it can show (monitor brain did this, not the PC ever)  (these are all OSD brain transmitted to the screen of only desktops.)
The older LCD used a back lamp ,cold cathode fluorescent lamps CCFL inside that love to fail, dead, go dim or go yellow.
The LCD matrix , is not a light emitter like CRTs were, it is only a contrast device.  (thus the background lamps must used)
 (that means it can not glow ever, like say a true OLED panel), 
The CCFL tube maker   claims 20,000 hours or 2.2years run full time)   (read short life span)
  (LED back lamps can last near forever 20+ years, I have LED clocks that are 42 years old and still run like day 1)
One more failure mode (of the many) is the...
The CCLF inverters also LOVE to FAIL as  do the tubes  
The inverter converts low voltage to high voltage that the CCFL needs in order  to glow CCFL. 
Diagnosis is very simple, in most cases, the first test, if the screen is black even when turned on and no Logo shows up or error warnings, first suspect a DEAD CCFL
Do the flash light trick below. (shine the light and turn the monitor on and of many times to see if any logo's show up, or errors)

Top fails: (first are old screens, with CCLF)
If the lamp is dead, in most cases the owner throws the monitor away due to a new display is a fraction of any possible repair bill.... (econ101) proof below.
 Walmart has  nice $50 display for sale, why not upgrade to LED display now.?
The Laptop screen is a whole other animal.
It has no OSD, nor warnings, the best test on any laptop is the flashlight test while hitting the BIOS hot key ESC over and over.
IF the laptop screen shows  this its not dead:

Finding the problem and fix it :  If Laptop jump to LT now.
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 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:
  1. Plug the monitors power pack in, and turn the monitor , the HP  (or you makers) LOGO must show up and  no signal waring for about 3 seconds or the monitor is bad. (jump to #4 below if this fails)
  2. Connect the monitor under test to a known working PC, turn on the monitor then the PC, the OSD screen can be commanded on with the front panel Monitor menu key.
  3. The display LCD-CCFL is dead weak, or its PS_inverter and do the flashlight check below.
  4. You Error no signal The VGA cable  can be bad, replace it or try a spare barrowed?   (you get this error even with monitor tried on other PCs)
  5. The monitor may also show ("im in sleep mode or power saver mode" in most cause this is the PC messing up. or the rare case of old 2002? monitors  , the super secret internal timer.
  6. The monitor is always best tested on a known working PC of any kind with a VGA jack (15pins) Dshell connector on its rear,  that many have, or if DVI cable /port monitor the same.
A good monitor will show the makers logo and no signal error each time the monitor is turned on, PC turned off.   If the monitor is dead look here for discounted monitors.
The HP logo and errors seen here, (no sig) are from the Desktop monitors internal Brain.  (not the PC)

Laptop  LT, only screens.  ( lots more to fail here, due to more parts in play and shared power !)   This is not a monitor it's only a SCREEN now.
The laptop has no OSD (like desktops do)
The laptop we first check that  we can get to the BIOS pages (on mine it's the ESC key)
  1. Connect the line power pack 19vdc 65watts or more to the wall power and Laptop connector.
  2. Remove  big battery that snaps into the bottom,  (if a tiny notebook , with no battery main classic that just pops out,  one must read the service manual to do that act)
  3. Turn on the PC laptop, if you see text the screen is not dead.  (see OS dead) {operating system}
  4. as you power on  hammer the ESC key (or the key that is listed in your operators guide)  ESC is HP key last 10 years. 
  5. The screen then give you text and options,  if that works, the screen is NOT DEAD,  see OS dead above)
  6. if screen is still dead,  no HP logo shows or the words, "hit ESC key to enter setup" show up do the flash light trick next.
  7. To further prove the screen is dead connect a Desktop screen to the LT read VGA jack. (if HDMI use that to a TV) if this works ok, the local screen is dead (Fn+F4 is the hot key to activate the VGA jack)
  8. more examples of black screens are cover here.  black-screens of death 
In most cases,  if the screen never shows, text the screen is dead, bad screen or bad CCFL tube /inverter card.
Some LT need this part to do the external tests. (lacking VGA/DVI)
This is my Laptop block diagram, the screen shown, at the large red arrow. This is LED backlighted screen and very reliable. The video card is seen here.

"The flash light trick" Desktop or LapTop  (just 1 minutes work and bingo ?)

I take my flash light, and point it to my black dead screen.  (I am hammering the ESC key, "flashlight pointed to screen, power on and quickly hammer the ESC key" BAM BIOS POPS. (or F10 key on 10 year or older HP)
or if you know windows is running, you heard it make music, ? or just  know it by the sounds of the HDD etc,,, then just use the flashlight, now. BAM, yah, got  DATA?
If I  see data here, this is BIOS but can be Any windows screen of any kind ,or even a login screens or BLUE SCREENS 's. See, it's not dead is it; only the Back lamp is DEAD, (the CCFL must be replaced)
This is the first CCFL test. (mostly before year 2010 PCs)  If testing any Desktop there you will see the monitors log show up , and then PC BIOS showup here.
      Wow the back lamp is dead !

When I see the above, (I have repaired many )  but I can  get this Desktop  monitor from walmart for near $50 and use it.  or a whole PC for  way  less !!
One can use a Desktop screen on your laptop in  pinch or at any time. (mobility here will cost you way more,  labor and parts.
All HP LT have service book telling you the steps to remove this screen and put back the new one. (some LT have no separate inverter cards but deep planted the display."hidden")

But if portable is necessary, then you must fix it, and below that is what I am doing.... (some just use and VGA external monitor for , cheap cash used and use  that forever)

Keep in mind that the LCD connector deep inside might just fall off, for sure if monkeys played here before and did not put back the tape to secure it like new.

A PC boots and runs its OS in a process. BOOTING LOGIC 101:
Power on,  the Desktop monitor shows its logo all by its self  then the PC side boots.
You see messages on all PCs at boot, the text (other than NO SIGNAL) is from BIOS.
BIOS boots the machine in all cases, LT or DT.
BIOS talks to you, if BIOS is dead there will be no booting to anything else.   (BIOS never self erases (99.99% of all bad BIOS his HUMAN damage)
The BIOS sends text  below and if a laptop shows HP LOGO top right seen here, clear as day, that means BIOS is alive , the screen is ok, and the PC may fail to boot next. Boot to the windows logon screen.
This also means the CPU can process data, the RAM bank must not be missing or BIOS will be dead. Test memory banks 1 stick at a time in BANK 0 slot.
If this message is gone, the CCLF is dead or main LT battery shorted out (remove it) or there is a gross loss of power inside the PC. (thus the Flash light test to see if it is only a bad CCFL)
BIOS/screen  is clearly NOT DEAD !

The  HP logo is BIOS generated on LT, even if HDD is missing we still get the above screen, even HDD/SSD and DVD drives missing, a key fact to know diagnosing any PC.
To prove that, hit ESC at power on, see it is  not dead, you now get the HP BIOS menu system. 
The PC  BIOS can now do error codes, via beeping or flashing Caps lock LED lamp.
Seen the above I now boot to any  CD/DVD or USB memory stick with Linux, Windows LIVE PE or any bootable media of any kind, see, the PC.
On my PC the F9 key is the boot choice key, I pick my Linux boot stick and bam Linux live runs (knoppix v7)  omg my PC is ok, just windows is BORKED. (scrambled or dead or HDD dead)
If you have the HP , install media kit boot disk 1, does it go to the install page? (see the PC is not dead is it?)
if your HDD is bad the F11 restore key will fail, as will F9 boot to HDD 0 (HP magic F11 OS restore, recover mode) or was slammed.
If you see the windows pages hang.  or shows any of the 50+ blue screens of death, then windows needs to be reloaded.
if windows shows errors freshly loaded the HDD may be bad.(run the BIOS HDD tests)
 See why WINDOWS IS DEAD. or See why windows is dead , here.


Windows can also show its updating the OS, or 50 other blue screens not one with the words Microsoft or MS or any clear markings as to the sources of said inane blue screens.  MS I guess owns the color BLUE, (wow)
Photo1 note the only clues here, HAL, Hal is the name owned by MS,  for hardware abstraction lay, (Video driver crash here , I my guess) and photo to is Updates,  we might guess that is MS and not my firefox updates (lol)

The MS Update can take hours, on a slow internet service or weeks on dial up.  (w10 is not nice for slow web connections ,ever) the other clue is the unhappy face, I guess MS owns that too..
The 50+ error screens all have codes, or clues. (to what is wrong)

One more inverter fix, in a very different way below is a LED CONVERSION kit.  I've done a few. $100 fix to.... so... you must either be rich or crazy like me, ..
If all you need is an inverter ?, ebay has them used for about $5 (the tubes can be changed but is not easy, youtube that, to get the level of difficulty , step one is remove the screen.)
Here I am upgrading the CCLF screen to LED Back lamp screen, see the new Inverter dead center. (the screen was cracked and wrecked,  so I upgraded it)
The new , Genius level inverter here fits vast numbers of laptops. The extra connectors do  that.  (this is a Toshiba.)

end coversions.

Solder balls from H3LL: (a short era)
CIRCA 2008.  (newer PCs just ignore this)
lead free year, horrors.  (this horror is a mix of bad design and allowing the PC to overheat) (blame is in Nvidia camp , I guess)
This began with USA government laws, banning lead (Pb) kicked IN and caused the below results,  just like all mandates, things go bad (for someone, even millions of folks) 
Best action by you is scrap the PC, buy a newer PC.  (get a  desktop this time? ) or HP 8540w. Buy something that has  GPU card inside. (buy a desktop and a dirt cheap chrome book for travel)
This is a surface mount device,  and uses solder pad/balls,  I bet moms oven can not fix this failure !!!
 (I will demonstrate this using a better LT PC, one that has  totally modular , VIDEO CARD)
(this can cause a range of wild and crazy symptoms, and for sure  intermittently and screen acts crazy, as the  LT base is flexed.)
One more clue is the rear VGA  jack fails (using an external monitor), too when the PC is flexed,  (GPU failures do that)
 The 2008 era, LT may have the GPU solder ball failures from H3LL problems cause by the USA Federal mandate of lead free solder, laws.{think Monkey wrench effect}  (yup, it was born dead, complex thermodynamic reasons, low melting point solder) 
The are 3 reasons for this failure, 1: not putting a steel stiffener frame on the MOBO, 2: a bad  brand of new Lead free solder, (too low melting point) and at the same time, if lap top vents are blocked you can overheat the GPU easy,
Some solder melts at 136f (58C)  not saying this was used, only saying they used the wrong solder,, my bench solder sn63 melts at 183C (361f)
Some users placed their laptop on a blanket , it overheats and the solder here was damaged. (like a perfect storm of bad, but is now cured by the makers)
Also some PC overheated fast and easy. (some LT makers just hid the problem by running fans full time or 2 times faster all the time) (preventing many dead displays)
If sitting on a beach at 120F in the shade, and the LT goes dead, are you surprised? Most will overheat like this and worse if the sun lands on the LT.
One LT, if you press hard on the J key  , the  GPU bad solder balls, connect and  the screen wakes up, or goes dead. (yup).
Or,  remove the key board and press on top of the GPU chip now,  does the screen wake up now? BINGO? bad solder joints you HAVE! (kiss off one MOBO) but not mine below, it's an Elitebook.

My GPU unplugs. (GPU means Graphic Processor Unit, or chip)  Yes the chip runs hot, and has heat sinks, as do those fast RAM chips seen here.
The large chip below is it, and will overheat if the heat sink is missing or fell off.  (loose or the thermal compound is cracked)
The other chips are dedicated RAM for the GPU. The RAM chips on mine have heat sink pads. 1mm thick (I reverse engineered them, 2 ways, the pad them self and the gap measured.)As seen here.
Do not let hacks fix your PC or they many make it worse not using proven heat sink compounds or pads, the correct thickness. 
Warning 2,  I see laptops failing for GPU too hot, I then check the heat sink and find that the compound is now hard as dried clue and brittle,  and is now CRACKED from natural LAPTOP flexing.  What ever they used there for compound is NO GOOD. I use this.

My Graphics screen driver CARD: below:  (HP Elitebook 8540w)  My LT has 3 card options. (speed)
I love only Laptops that have a card that unplugs, (you do get what you pay for here!!). (not only that, but I CAN UPGRADE IT for gaming, or for CAD/CAM or for Video editing extreme. Yes, PCs are versatile.)
Some cards sell for $20 used.  (what a deal and not one has Solderball problems !)
The solder balls (SMD) are under this big green chip below, called the GPU, graphics processor.  (the conditions of assembly here are complex, Re-flow methods in an OVEN)
It runs real hot, the better and faster the chip the more heat it expels (like gaming does),  The balls can not be home repaired,  doing a ball remelt in moms oven is 100% failure event, I can replace my card but most cheap laptop owners the MOBO is bad now.  $150 used part. or more.
This example below never ever fails for solder balls , but the photos of my GPU are very clear, and you can see no human can go under there, and fix bad balls. (only a re-flow oven might but at home is  hard fail to try)
HP 8540w, is the best LT HP ever made, I hoard them.!
The test to see if this chip is bad is press on the Keyboard "J" key the chip is below that key, on your LT the pressure point would be different, read the service book to learn that location.
or learn to twist gently the whole base of the LT.  (a bad screen can be tested the same way, twist the screen bezel, gently) see lines,? yes, then , bad a screen.
I can also remove my keyboard and then press the GPU chip to my hearts content, to see if the screen acts up.  (2008 is the year of horror for said chips)
A savvy Tech knows there are many  classes of failures, (lucky me , no hydraulics or pneumatics. here.)
  • Bad power, (always first this) (does it run with no battery?)
  • bad electronics,  (or electrics like motors are electric)
  • bad connections  (cables and jacks)
  • Thermal dynamic problems. (overheating)
  • Fans dead,  the motor in the fan dead packed in lint or hard disk drive motor is dead (silent)
See why PCs over heat, here.

NOW LEGACY HARDWARE.... (cry a river? song played now?) History and Evolution matters, it lets you know what you have before you start testing things.

CRT and CCFL are now legacy hardware.  : "Cold Cathode Florescent Lamps" CCFL for short !
Over 10 years old falls into that pit of legacy hardware,  and all the bad things with it, (lack of support, lack of parts tops that list)
Monitor or Laptop SCREEN BACK LAMP  failures (CCFL) are #1 failure rate items up to 2010 year when LED came on the market.
CCFL fail in these modes: Dead, Dim, Yellow, blinking (strobing) or random works or not! (in as low as 20,000 hours use)
Acid test:
Run Notepad (start button type notepad) if that shows yellow for white, the CCFL tubes  1 to 4 are bad.  See the next photo?, there they are explosed by me.   Right click image 2 to zoom it.

HP Made many CCLF Laptops, from year 1997 (first LCDs) LCD beat CRT's sales in 2010   
CRT were introduced by IBM in 1981 (MDA, EGA, VGA , DVI followed, even HDMI now) all this is in the WIKI to read.

To change them tubes, it  can be easy or near impossible , some are so deep in side that damage happens no matter your skills.  see and easy one first here.
CCFL all fail in these ways :turn yellow Dim out, then blink, then die dead.  Some might wake up for a day, or 1 hour, but will not last much longer if you keep doing that, those are the death thows of any CCFL tube.
They sell tubes here.
Here is fix,  if you like to upgrade CCFL to LED, . (easy or hard or impossible are all possible here)

The plot can thicken easy, too easy if you have U tubes inside, good luck finding the correct size. ( 3 U-tubes become 6 long straight tubes)
If it has U Tubes, shaped,  we can  (glue in  2 straight tubes wired in series can work, nothing to lose trying)  Finding those is near impossible. (YMMV)
No 2 monitors or Laptops are the same, each is custom design and complex disassembly.  (as you can see, I know how in above link)

The CCFL the cold cathode Florescent lamp tube.  ( these can go dim in 2 years of continuous usage (no sleep/hibernate modes used) 20,000 hours is the typical life spand (yes ,short)
Lamp life is defined as the brightness decreased to 50% of the original.
 LED's can go for 20 + years full tilt.  Most CCFL lamps used here, ended in the year 2010.
Some tubes need 500v to 1000volts and 40khz Sine wave, and by level of dimmer setting.
The Phosphors inside age and go dim fast from these effects below:  As they dim they love to turn YELLOW.

Due to degradation of phosphor from Hg consumption . (Hg = Mercury gas, very TOXIC too, do not break them and sniff them, okay?)

Ion UV bombardment from the discharge column may be the attributing actor in depreciation of the Phosphor (age effects many)

Ion bombardment of the phosphor over a period of time can cause the inner layer surface of a phosphor coating to become non-luminescent (more aging effects)

Ion bombardment over time can cause some phosphors to have a greater tendency to absorb mercury. (as you can see, now, CCFL's SUCK for these reasons.)

See inverter fails next,  after some history below and HP secrets by model.

HISTORY and specific models of PC that love to fail for bad CCFL:

THEN CAME WHAT? "LED back lamps came later"
The bright white LED was introduced in September 2003 by Cree, but it took many years  for PC makers to latch on too this device. (slow my guess, is was  due to LED costs in 2003 ,or near)$2 a pop is super expensive.
CCFL's ended about 2010 in Displays.(LED takeover) Just as CRTs died down fast, and for sure helped with the push over.
These tube lamps can fail, or go dim or go yellow or flicker or the inverter power supply for it is bad.
Do not forget that many old CCFL laptops you can buy a LED conversion  upgrade for many, as seen in ebay...(For HP621 / G60 / DV6 / CQ60, and more )
This HP only ,  table is not complete: (one trick is to pretend to buy a CCFL for you screen, if can't? then it has none.) Trick 2 is to read the service manual, see words toxic for Hg Mercury , bingo CCLF.
Old Laptops. CCFL  (most)  "The PCs not to buy used"
Most old  Compaq CQ series , CQ40,50 ,60 61, all made before 2010.
Compaq 6500 series  6700, 6800, 6900...  8700's
TC1000 and L2000
519-535  hp 500 series
DV2000 up to  9000 series.
ZX5000 series  , ZD8000
Compaq Nx series, nx6000? nx9400  
N600, NC8000 series
nx8200 series
DV4,5,6,7,8, series.
and lots more..G60 ,G61, G70
Very old Elitebooks had CCFL 6530s,6930s,8510,8530,  (never 8540s) (oddly my 8540p/w  are LED)
I think Elitebook codes, are  xx30 and xx10 means CCLF inside.. on Elitebooks.

Monitors with CCFL , and internal HV power board. (seen below)
L15xx series,  L1503 is common (the first 2 numbers are size wide)
L17xx series
vs17, vs19. VS15 bit VS19 is LED.
and more. 
but a warning; I saw some old names like L- Series,a monitor with LED the last year it was made and  a new power board inside to match.
The introduction of LED started with large screens at and above 20" , then moved to more narrow screens.(cheaper screens last).
INVERTERS: (first Exernal, monitors then Laptops last)
Below I will show some old HP External desktop monitors.  (first is the PSU the power supply inverter unit (PCB) "Printed Circuit Board"
This is a  HP L1711  Monitor PSU that uses 2 High voltage jacks at left, to run the CCFL tubes.
 The silk screened words there clearly show HV Caution. Giving this lil' secret away. Almost all HP external monitor PSU's that have CCLF use the same look alike  HV CCFL jacks.(hint 2)
Note how the jacks are isolated (lots of PCB space) so that HV does not ever land on that jack to the right and blow itself to kingdom come. (logic chips HATE High voltage HITS, read up on ESD?)
They (the Engineers) know  this PCB will be buried in dust too and dust conduits electrons.; Shock hazards here too,  500volts up.... wider the screen , the more volts.

INVERTER cards do fail, x10  less often. (than lamps ) 
Many CCLF screens have an out-rigger Inverter board that converts,  5vdc? to 500vdc. for the CCLF tube to Ionize and glow.  
The tubes love to fail or go dim, yellow or flicker, and so does the below love to fail. Buy them used on ebay.
Some Inverters are buried deep in the screen where no man can go or worse can't buy them at all , only a new screens cures this.
See the old DV2000 inverter its really a DC to DC converter, low volts to high voltage (and can shock you playing with it)

PC External monitors , if these words turn yellow the TUBES are BAD.
On Screen Display:
OSD is a menu
that the Monitor Brain inside presents to you, on demand, Push the Menu button, below Mr. OSD . as seen below. The PC brain (CPU) does not do this at all.
This is a new OSD screen ( monitors brain does this not PC) (key features to try are, brightness, and factory reset and OSD lockout)
Relic , legacy monitors look like this below:. Even CRT monitors had this. (the most old CRT never did !)
circa 2000? old. On the oldest monitors say year 2000, there can be SLEEP timer here, TURN IT OFF NOW , keep it OFF.

L1703, try factory settings yet, brightness, color temperature, ? You can even custom set the RGB color levels as you like.
If you view a white screen , say in MS NOTEPAD,  and it's yellow looking not pure white, the CCFL is bad. and colors will be muddy.
To get this OSD screen push the front panel monitor button called Menu (or select).
The OSD lock feature can be turned off by holding the menu button for 10 seconds to 30s. max.
The OSD can  have  a test pattern page, so if the test pattern looks wrong, you know for  a fact the display is failing or set wrong.(read your users guide yet?)
This HP test pattern inside the HP OSD menu's is really a nice HP feature, so you can see if the monitor is ok and can be used to tune the colors as YOU see fit.
Learn that monitors made from 2000 to 2010 year, had OSD changes made (radical) for VESA and EnergyStar rules/laws. 
The classic example of that is around 2004 they dropped the internal sleep timer (I hate). (always turn off said timer  first)
For sure the video cables can fail. (try another cable yet?)

RANDOM acts of death,  Impact damage.

Surely the above is clear what's up,  what is wrong, no words really need be said of you ever saw how fragile LCD really is, one smack is all it takes. 
Kiss off a $100 bill. too. plus LABOR charges  (laptop or desktop, same damage possible)
more Captain Obvious damage, hint, cracks do not need to be seen , the crystals fail by self.

CRT  Cathode Ray TUBE Monitors,  ditch them, is best idea.

If you hit this below CRT  hard enough it IMPLODES. (below) Do not play inside as the 20,000 volts will not make your day. Not at all.
If you have one 2 choices?

  • Pissing on a running lawn mower spark plug !
  • or messing inside here,  pick pissing. 
Read it carefully:  (learn  that nobody with brains volunteers to take the 20kv hit grounded and through the chest. NOBODY.!  and few live to tell about it.
 If you put that energy trough your heart,  who knows what happens. As low as 10uA (micro amps) current can stop a heart and high voltage can puncture the skin and that is super dangerous.
That nerve on the heart? Don't play games with that body part, ever.!
If you do take  hit here, the pain is at grade 1000 out of 1000,  you will never forget it. (It can throw you across the room and get hurt real bad doing that too or hit others or cause huge cascaded damages...)

 The CRT is a large HV capacitor. (that holds charges for a very long time or seems near forever.) The glass is near a perfect insulator is why.!  Glass is !
CRT's;   the CRT needs a trip to the  Recycle center  fast.
A working CRT is amazing today.
Most of the CRT's  are dead  today or the RED GUN is way low, (I can be raised higher in the Menu's of most OSD.)  If the CRT fails , most parts are not found today... (good luck sourcing  relic legacy part like this)
20" Monitor. below.

version 3.  7-29-2017   (no PC diagnose here this is only MONITOR or screen failures)