All Posts Tagged With: "Troubleshooting"

Only Reply To A Post If You Have Something To Add

When researching a problem on the Internet, a lot of times you will find message boards and blot posts to be very valuable. If during your research, you come across a post which shares the problem you are having, only post a reply to it if you have something valuable to add to the troubleshooting process.

Often times, you will see a problem explained in great detail only to find a slew of follow up posts which basically say “I’m having the same problem”. This adds nothing to helping the issue get resolved. Instead, only post if you have something constructive to say such as troubleshooting steps you tried or any additional information the original poster didn’t supply. Doing this allows others to have a better understanding of the problem you are experiencing which hopefully leads to a solution.

What Causes A Router To Fail?

In the context of this article I’m referring to consumer grade home internet routers, as in the type that typically have one WAN or "Internet" port and four LAN ports.

It’s quite difficult to pin down what specifically causes a router to fail. For example, if you have a dead router, hand it to an electrical engineer and asked him or her…

"Can you tell me what caused this thing to die on me?"

…the engineer would not say, "It was x that killed it."

Instead, testing would have to be done to determine the cause, and it would take a while. Maybe it was crappy firmware. Or an electrical short. Or it suffered from some heavy EMI. Or it was tiny bits of condensation. Or it was something as simple as a bad power adapter. Or something else entirely. There are any number of ways to kill a router.

It’s more important to rule out false positives and know how to recognize warning signs, if any, that a router is about to fail.

Ruling out false positives

False positive for a router failure: Google Maps

I know of one real-world example that can be replicated easily, making it appear like your router is having a problem when it in fact isn’t.

Using the web site Google Maps on the Windows operating system with any web browser, if you load up a map then quickly pan the map in combination with some fast zoom in/outs, this will make too many network requests and cause your internet connection to "freeze" for up to 90 seconds.

Google Maps works in such a way where it contacts several different servers at once when panning/zooming around the map, and using it too quickly will time out the connection temporarily in Windows.

You may say, "But my router can handle a ton of connections. What gives?"

Since Windows XP Service Pack 2 up to present with Vista and Windows 7, the Windows OS is purposely engineered to limit network requests whereas previously it wasn’t.

End result: Not a router problem. It’s Windows doing it – by design.

I have only been able to replicate this issue using the Google Maps web site. Google Earth doesn’t have this problem and neither does Yahoo! Maps, Windows Live Maps, MapQuest or any other mapping site. Or any other web site for that matter.

To rule out my own router as the problem, I tested this on another ISP using a router made by another manufacturer. Same result. Time-outs with Google Maps – but only on Google Maps when using it heavily as noted above.

False positive for a router failure: Bad network cable

A new router obviously won’t cure a bad network cable. If troubleshooting a router, always replace the network cable first, both to the PC and to the cablemodem.

Ruling out a bad port

It is not outside the realm of possibility that the port on the router that connects the network cable to your PC’s network card is bad. If you’re plugged into port 1, try port 4.

Why 4 and not 2?

Because it’s the furthest away from the port which may be causing the problem.

To note: Having a bad port is an unlikely situation, but as said above it’s not outside the realm of possibility.

Are there warning signs when your router will fail?

In most instances there are no warning signs when a router is about to stop working. You’ll be using the internet normally and then *poof*, dead connection. Modem lights look fine but router lights are either all on, all off or blinking in a "weird" way.

More expensive routers will give at least a little bit of warning (usually 4 to 7 days) before failing altogether, seen in the form of random disconnects. One reason this this may occur is because the crash recovery isn’t working properly any longer, causing the connection(s) to drop at random intervals. And that’s all the warning you need to know that yes, the router will stop working soon.

What can you do to extend router life?

It’s easy to extend the life of your router if you follow these simple steps:

1. Keep it off the floor

Some people simply run out of desk space and "demote" the router to the floor. Bad idea, because that’s where all the dirt is. And even though your router most likely has no fans, that doesn’t mean dirt cannot get into it and end the router’s life early.

2. Avoid cable stress

Network cables that are pulling on their ports is just bad news. If you’ve got a network cable that’s just slightly too short and has tension on the port it’s connected to, do yourself a favor and just buy a longer network cable.

3. Keep it away from the PC

Common occurrence: Seeing a router sitting directly on top of the PC. It shouldn’t be there. The PC is vibrating, even if only slightly. Those vibrations can lead to early router failure later.

Not all PC cases vibrate, but many do – especially when the optical drive is in use.

4. Never shut it off unless you absolutely have to.

I have heard the story more than once where someone shuts a router off, turns it back on, and it dies.

Unless troubleshooting a network connection, there’s really no reason to ever shut a router off.

5. Don’t upgrade the firmware unless it’s required.

Router firmware updates are like BIOS updates in the respect that you should never apply the upgrade unless there’s something specific in it that fixes a legitimate problem. If there is no problem to be fixed, don’t do it.

Read the release notes for router firmware updates first and always.

If from the release notes you learn the update patches a security hole or two, then yes, you should apply it immediately.

If on the other hand you discover the update doesn’t fix any security holes (which most likely means that none exist), add any features you need or the like, don’t do it.

Have you ever had a router die on you? If so, were you given any warning?

Post a comment or two and let us know. Remember to list your router make and model.

Fixing A Corrupt Recycle Bin

A strange problem that I ran into recently on a couple of our machines was what appeared to be a brokent recycle bin. Basically, you delete files to the recycle bin, but if you open it there are no files listed. When you try empty the recycle bin, it tells you that X number of files will be deleted so it knows files are there.

The fix I found was to create another recycle bin. Unfortunately, when you do this, the existing files cannot be recovered, but at least it gets you a functional ‘new’ recycle bin. I am still not exactly sure what caused this, but if it happens to you, at least you won’t have to do a repair or reinstall of Windows to fix it.

See More Info In Windows Task Manager

When you open Windows Task Manager and go to the Processes tab, you see a lots of good information such as the actual process executable name and current memory/processor usage. Did you know you can customize the columns shown to include a lot more information?

Just go to the View tab in Task Manager and click on Select Columns. In this list you will find lots of additional information you can show. The columns I use are:

  • Image Name
  • CPU Usage
  • CPU Time
  • Memory Usage
  • Peak Memory Usage
  • User Name
  • Base Priority

I find this is a good blend of a ‘quick and dirty’ view as well as troubleshooting information without being overwhelming.

Note: If you use Process Explorer, you can use this trick as well.

Find Out What Is Behind The Scenes With ’svchost.exe’

If you look at your Windows Task Manager Processes tab, you will probably see several copies of ’svchost.exe’ running. This is normal and is the process name that your background services run as. If you ever are curious what each one is actually ‘hosting’, here is an easy way to find out.

  1. Download and run Process Explorer.
  2. Double-click on a svchost.exe entry.
  3. Look at the Services tab.
  4. You should see a list of the respective service names under the ‘Display Name’ column. Click on the entry for more information.

This is a really handy feature to know not only for informational purposes, but for troubleshooting as well. If a certain instance of svchost.exe is eating up a bunch of memory, now you know how to find out what it is doing.

Troubleshooting A Sluggish Machine

It’s pretty obvious I am a big fan of the Microsoft Sysinternal tools as I have run many tips on them in the past. I am also a big fan of Mark Russinovich’s (the driving force behind Sysinternals) blog where he covers a lot of interesting and in-depth Windows topics.

In a post Mark released recently, he discusses how he troubleshot a sluggish Windows Vista machine (please spare the Vista jokes). Obviously, something more than a reboot was involved in his troubleshooting and he discusses, in great detail, how he was able to track down the causes of the problem using Sysinternal tools. The thing I really like about this article is he makes it all seem so easy and explains it in a way you can actually follow along.

Anyhow, this is a great 5 minute read and goes to show that you really can find the cause of just about any computer issue you encounter.

View Process CPU Usage Over Time

If you are trying to track down a specific process you think might be hogging your CPU power, rather than doing isolated ‘unit testing’, simply use Process Explorer to track down the culprit.

The steps are simple:

  1. Open Process Explorer.
  2. Locate the suspect process in the list and double-click it.
  3. In the properties dialog, go to the ‘Performance Graph’ tab.

In this tab you can view the CPU usage on an easy to read graph. Just hover your mouse over the CPU spikes to see the exact stats on how much juice the process is using. I use this to detemine how much CPU monitoring programs are using to determine if I should keep them running in the background.

Regardless, this is a pretty useful trick to know about to help track down greedy programs.

LCD Monitor Troubleshooting 101

image It’s a safe assumption that the vast majority of computer users today use LCD monitors. It is in fact a very reliable technology and it’s not often that you hear of one breaking. But being that it’s an electronic device, yes it will eventually fail.

How long does it take before an LCD fails completely?

Usually about 5 to 7 years.

What is the first thing to "go" on an LCD monitor?

With a free-standing LCD (i.e. one attached to regular desktop computer), the backlight is usually the first thing to break. With a laptop a whole host of other things can go awry. More on that in a moment. When a backlight fails, the picture will get extremely dim. It will still work but be almost unreadable.

Is it worth it to repair an LCD monitor?

Never. The cost of repairing an LCD monitor will usually cost more than replacing it outright.

Common issues with LCD monitors

Solid horizontal and/or vertical lines

One day you will turn on the monitor and these brightly colored lines will appear with no way to get rid of them. This is a hardware fault and there is no fix for this. Replace the monitor.

Monitor takes a while to "warm up" after starting it

You turn the monitor on and it takes a minute or two to reach full brightness. This is a backlight issue. You can still use the monitor normally until the backlight breaks (which it will eventually).

Monitor flickers on and off randomly

This is laptop-specific. The LCD ribbon connector cable is damaged from normal use of opening and closing the lid over time. This can be repaired. The monitor does not need replacement, but the ribbon connector cable does.

If you’re brave enough you can order this part from the OEM manufacturer and replace it yourself. It it normally located under the left-side hinge. It is not easy, but certainly cheaper than replacing the entire display.

Suggested course of action is to locate an authorized computer repair center and have them replace the ribbon connector. It will cost anywhere from $60 to $150, labor included. This may sound expensive but it’s still cheaper than replacing the monitor itself which will cost a whole lot more.

Corners or one side of monitor appears dimmer than the other

Again this is a backlight issue. There is no fix. Deal with it or replace the monitor.

Everything "goes green" or "goes pink" or "goes red"

For laptops, again this is the ribbon connector cable. Replace it. For desktops, replace the monitor cable which may or may not fix the problem.

"Wild patterns" appear for no reason

It will look something like this:

image

No fix for this. Monitor is busted. Replace it.

Troubleshooting and FAQ

Q: (Wired/Wireless) All my router’s lights are on and will not go off. When I try to connect to the router, no network connectivity is present. What should I do?

A: On all routers there is a “reset” option. It is a button physically on the router. If after a reset this does not work – power off the router, wait ten seconds and then turn it back on.

Q: (Wired) My router can’t seem to establish a connection to the internet or to my home network. All the lights are on but the data does not seem to be transferring. What can I do?

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Test Your Mail Server Via Telnet

This tip is for you system admins out there: If you are ever troubleshooting a mail server which is either not accepting or not relaying messages, rather than using the “send and wait” method of testing, telnet directly into the mail server to do your testing.

The linked Microsoft article walks you through the entire process of how to send an email from a telnet session. While the article speaks with regards to Exchange Server, the exact same commands can be applied to any mail server. I have used these exact steps many times to test customer’s mail servers to diagnose problems.

The great thing about using a telnet session is you can use any sender or recipient email address and can immediately see the mail server’s response to each of your commands instead of having to decipher an NDR message.

Repairing Or Uninstalling Corrupt Programs

I recently ran into a problem on my machine where my installation of Office 2007 became corrupted. As a result, I was not able to repair or uninstall it from the Add/Remove programs menu. Instead of giving up and going through the major hassle of reinstalling everything, I came across a more elegant (and much faster) solution: The Windows Installer Cleanup Utility.

This utility simply “tricks” your computer into thinking a program is no longer installed on your computer, so you can then go back and reinstall it. In my case, it worked perfectly as after the “reinstall” I didn’t have to activate my copy of Office 2007 again.

Usage is simple enough, just install the program and then run it. You are presented with a list of all programs which were installed using the Windows Installer Service and you just select which ones to delete the installation information for. Once you have done this, you should be able to reinstall the program with no problems.

A Great Example Of How To Troubleshoot

I ran across a very interesting read today, an article titled “The Case of the System Process CPU Spikes“. What made this an interesting read was not so much the article content (although I thought it was very informative), rather the methodology used by the author.

In a nutshell, the article walks through the problem (a continuous CPU spike) as well as how the author proceeded to troubleshoot the issue. He used several freely available Microsoft tools to diagnose the problem which turned out to be a network driver.

Regardless of whether or not the subject matter is applicable to you, I think the process used is something we can all take from this. Virtually any problem can be solved by thinking logically and using the right tools.

.NET Cleanup Utility

One problem I ran into recently required me to uninstall my existing .NET Framework and reinstall. No big deal, so I thought. When I went to uninstall .NET, it immediately errors out. I restart the computer, same problem.

Well, this frustrating problem was easily solved with the .NET Cleanup Utility. Simply put, this utility forcefully removes your existing .NET installations so you can reinstall them. Make sure you heed the author’s warning through:

1. This tool is designed as a last resort for cases where install, uninstall or repair did not succeed for unusual reasons.  It is not intended as a substitute for the standard uninstall procedure.  You should try to perform an uninstall from Add/Remove Programs before using this cleanup tool.
2. This cleanup tool will delete shared files and registry keys used by other versions of the .NET Framework.  If you run the cleanup tool, you will need to perform a repair or reinstall for all other versions of the .NET Framework that are on your computer to get them to work correctly afterwards.

This is a great tool to keep handy for those problem PC’s which might be having the same problem I was.