Krynn's medium-level diagnostics for common computer problems.

Krynn72

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Krynn's medium-level diagnostics for common computer problems.

NOTE: This is a work in progress. I have only done the first two sections so far. I want people's opinions on whether or not this might be a helpful guide, if I should write things out differently, etc. I'm looking for critiques on presentation, and suggestions on other topics (I've got a list of things to talk about already, but if you think there should be something on here, let me know). And of course, if anybody happens to know a better way of doing things than I'm doing them, I would very much like to know it. And if I'm wrong about something, also let me know. Some of the more advanced things I only diagnose at work, and let more experienced techs do the actual fixing, so I may have some minor misunderstandings of what they do.

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I'm writing this guide because I am bored and secretly want to be one of those guys who makes internet guides. What follows is generally my initial tests and thoughts whenever I see people with a certain problem with their computer. It is not exhaustive. I've broken it down into basic categories to make it easier to jump to sections relevant to you. I deal with a lot more laptops than I do desktops, so a lot of this is written with laptops in the back of my mind, but I will try to point out key differences if I think of them. If any methods overlap I may refer you to another section of the guide.

Section 1: Display Problems
The most common display problems I see are:
A) No display at all, yet computer looks like its on (power light is on, fan is on, etc)
B) Discoloration or display artifacts
C) Display is very dim
D) Display cuts in and out or flickers when the LCD moves (on a laptop)

So lets go through these one at a time.

A) No display at all, yet computer looks like its on (power light is on, fan is on, etc)
There's two common causes for this sort of problem. The first, is a simple fix. Many times there is simply a static electric buildup in the motherboard or RAM. This simply needs to be discharged. To so so, simply unplug the computer from the wall, remove the battery (if its a laptop), and remove the RAM modules. Then hold down the power button on the computer for approximately 30 seconds. After that, reinsert the RAM modules, reconnect the battery and/or power cable and test it out. If it works, great! If not, then you've got bigger problems.

The second and most common cause is that the video chip overheated. What happens when the video chip overheats is basically the solder holding the chip onto the circuit board gets so hot that it loosens enough for the chip to actually separate from the board, or simply no longer has a sufficient connection to work. If you've ever had a “Red Ring of Death” on your xbox, then this is what happened to it. If this is the case then the most common fix is is a Reflow. Reflow Soldering essentially reheats the chip and solder again along with a “solder paste” and attempts to reseat and recreate the proper connection with the board. Some people like to do “makeshift reflows” using their oven, but unless you really don't care if you destroy the component entirely, just take it to a professional repair shop. This can be an expensive fix however, and it may be worth just buying a replacement video card, or even replacement laptop.

Sometimes that's not the problem either though. If that's the case, then most likely there is a failure with either the motherboard, or the video card/chip itself. At this point I'd say just double check your connections, and test with another video card if possible (laptop users... sorry but you're out of luck there, might be time to get a new computer or drop it off at a computer repair shop and expect a expensive quote).

B) Discoloration or display artifacts
This is usually due to a failing video chipset. Often there's not much to be done but to replace it, if possible. You can try to install the most current drivers for the video card (obtained from the manufacturer's website), and sometimes it just needs to be reflowed as per above.
C) Display is very dim
This is most commonly due to a bad lcd backlight. If you have another monitor to test with, see if that works any better. Most laptops also have a VGA or HDMI video output for you to test with. I usually see this problem with laptops, and almost always with older models. That is because they used to use CCFL backlights (essentially a florescent lamp) to light up the screen. These require a inverter as well, which can sometimes also be the problem. Both of these components can be replaced, but I'd recommend taking it to a professional as the backlight is difficult to do, but the inverter is not so bad. Its also possible to just replace the entire screen. Be aware though that CCFL backlit screens are essentially phased out at this point, and the cost of getting these parts can be surprisingly high. LED backlights are the standard today, and generally don't have this issue.

D) Display cuts in and out or flickers when the LCD moves (on a laptop)
This one usually the LCD cable. There is a cable that connects from the motherboard to the lcd and it runs through the hinge. Its designed to be flexible, but enough opening and closing can sometimes wear it out. Replacing this piece can sometimes be a pain as you need to open up the computer down to the motherboard, and then open up the LCD assembly as well.

I have also seen it where sometimes it an issue with the control board on the LCD itself. Basically sometimes where the cable plugs into the control board gets damaged. Usually the only way to determine (unless its visibly damaged) this is to replace the LCD cable and see if it works.

Section 2: Power on problems
This sections will be pretty short as there's only a few things to look for.

For desktops, usually when it doesn't power on simply means the power supply failed. This is an easy part to replace, just make sure you get a power supply that is the same wattage as the one you had, and replace it.

For laptops, often its just the AC adapter (charger) has failed. If you have another one, with the same voltage and amperage, you can try that one. You can also try removing the battery, and try turning it on with the battery out of the unit and run off the AC adapter. Sometimes the battery causes a short circuit and just taking it out makes it work again. It can also be an issue with the DC jack on the laptop. This is the port you plug the AC adapter into. Take a small screw driver or something like that and see if you can push the dc jack around. Don't push too hard, just enough to see if it wiggles around. If it does, then its likely that the dc jack needs to be replaced or re-soldered back onto the control board.

For desktops or laptops, another issue that could cause power-on problems is a short circuit. This can happen in many spots, so its usually hard to pin down. A lot of times its the USB ports, where some of the metal leads in the port are bent out of place and touch another bit of metal it shouldn't be touching. You can replace the usb ports, or simply disconnect them if this is the problem. You can also try just unbending the metal pieces, but you still probably won't be able to use the port and I'd rather be safe and disconnect it entirely to prevent it from happening again.

Be aware, shorts can often damage other things as well. You may find that if you find and fix the short, and get the unit to power one, some other things may not work, and may never work. Shorts are bad like that.

Also its worth noting, that the majority of the time I see game consoles not powering on, its either because the power cables are bad, or the USB ports are bad. Rarely do I find it to be something else.
 
EDIT: um, don't know why its showing an empty spoiler tag before each of mine...

NOTE: This is a work in progress. I have only done the first section so far. I want people's opinions on whether or not this might be a helpful guide, if I should write things out diferently, etc.

I'm writing this guide because I am bored and secretly want to be one of those guys who makes internet guides. What follows is generally my initial tests and thoughts whenever I see Krynn with a certain problem with his posts. I deal with a lot more parrots than I do dogs, so a lot of this is written with parrots in the back of my mind, but I will try to point out key differences if I think of them. If any methods overlap I may refer him to another section of the kennel.

Section 1: Tag Overdose
The most common tag problem I see is:
  1. ****ed up spoiler tags

So let's go through this one at a time.

A) ****ed up spoiler tags
Well, like a fool, you use the WYSIWYG editor, so you have no damn idea what tags are really going into your post. And this is a problem because sometimes the editor injects a bunch of useless tags in your post for no reason, and you have no idea that it happened. In your case, after using the size tag, it tagged everything else in your post with default size tags, including each individual spoiler tag. This ****ed things up right good.
Solution: Use the bb code editor that lets you see your damn tags.
 
Fixed. Thanks for the confusing and sarcastic "tip". Nerd.
 
grilling of the century

You just had to go ahead and bring a dog down a level did you? He was just trying to make a difference.

And now I'm going to bring you down a level.

You spelled "differently" wrong in the first paragraph

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Is the first fix for missing video signal really the steps outlined above? That seems weird, but if it works, it works.
 
I'd say roughly 15-20% of people who come into our store with that sort of problem leave five minutes later with a fully working computer after we do that for them.
 
I baked my gfx card once. Luckily it worked for me. It was a last resort since i had no cash for a replacement.

It is crazy the amount of simple things that could be fixed in seconds that computers end up getting binned over. A friend of mine spent hours trying to figure out why his new build wouldnt boot. I arrived, looked in the case, plugged in the 4-pin cable he 'thought he didnt need' and everything was fine.

Says he who didn't check his RAM last week before embarking on hours of pointless crap cos he should have checked that first... *sigh*
 
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