Archive for February, 2010

Troubleshooting USB connections

February 26th, 2010 2 comments

Having problems with your USB connections?

This can be a tricky problem to troubleshoot because of the fact that each USB device requires different hardware settings, which can conflict with other USB devices. Since multiple USB devices share a single path into your computer, it can be confusing (and time consuming) trying to isolate the problem.You might be dealing with driver issues on a single USB device, compatibility issues between the devices plugged into the same USB slot on your computer, or even a problem with your USB cord or slot in your computer.

Before you start troubleshooting a USB problem, double-check the fundamentals: Does your USB cable have a good connection? Confirm that any USB hubs are properly connected and plugged in to powered electrical outlets. Many failures can be traced to unplugged equipment or devices that are plugged into outlets that are not receiving power.

To isolate the problem, have a simple USB device that works properly on another computer, such as a USB mouse. You can test this device on the computer experientcing the problems to verify that the USB port, not a faulty device or cord, is causing the problem. Here are some other common issues with USB connections and how to fix them:

  • No USB device will work

Possible causes: Operating system compatibility, controller/hub compatibility, configurations for USB controllers, controller drivers

Make sure that your operating system supports USB, then check all of your devices to make sure they are supported by the controller. Next, check the controller’s settings and drivers. (Each of these things must be compatible with each other.)

  • All devices occasionally stop working at the same time

Possible causes: Controller drivers, Power management, USB controller configurations, bandwidth

Bandwidth can be an issue if several devices are transferring large amounts of data. Common devices that hog bandwidth include printers, scanners, hard drives, cameras, and DVD/CD drives. To solve this, you might try dividing the USB devices between different USB root hubs.

If your system experiences sporadic controller failure, you probably have a problem with power management. You might have bus-powered scanners or hard drives that are drawing more power than your computer can provide. If your computer requires more power, try replacing your computer’s power supply with one that provides more watts.

  • Several devices work fine, but others won’t work

Possible causes: Controller/hub compatibility, USB controller configurations, power management, controller drivers, device drivers, bandwidth

First move one of the working devices to another root hub to see if the problem is in a particular root hub or with the devices themselves. Next, remove external hubs from the equation to see if they are the problem. Try the problematic devices individually on the computer. If they work, it’s either a device driver or power issue. If they don’t work, it’s a controller compatibility issue, a device driver problem, or a lack of bandwidth. To solve compatibility issues and driver errors, try updating the drivers.

  • Several devices occasionally stop working at the same time, while others are fine

Possible causes: Power management, device drivers, bandwidth

First, try to isolate the particular event that’s common to all failures. Your system might be experiencing a sporadic controller failure if your devices are split across root hubs. Try moving the devices to another root hub to see if the problem is in a particular root hub or the devices themselves. Remove external hubs from the equation to see if they are the problem. Try the problematic devices individually on the computer. If they work, it’s a device driver, power issue, or bandwidth pinch.

  • One device never works

Possible causes: Device drivers, Controller/hub compatibility, Power management

If the device works on another computer, check to make sure it is compatible with your controller. If your device is bus powered and it never activates, lights up, or registers with your computer, then a power issue may be to blame. Next, check your drivers to see if they are compatible or need updated.

  • One device occasionally stops working

Possible causes: Device drivers, power management, bandwidth.

Again, isolate the particular event that’s common to all failures. Move the device to another root hub to see if the problem is in a particular root hub or the device itself. Remove external hubs from the equation to confirm they are not the problem. Also, try using the device when no other USB peripherals are connected. You probably have a driver problem, but it could also be a problem with the power or bandwidth.

Solving USB Issues:

Operating system compatibility
Several operating systems don’t support USB:

  • Some Windows 95 releases
  • Windows NT
  • Mac OS prior to 9
  • Linux kernels prior to 2.2.7

If you’re using Windows 95, go to, check the FAQ, and download the USBReady.exe program, which will tell you if your Windows 95 computer is USB compatible. The new USB 2.0 standard may require additional drivers or patches that aren’t included with the OS. Check the device’s documentation for more information.

Controller/hub compatibility
USB computers manufactured more than a year ago are limited to USB 1.1 devices. USB 2.0 is much faster and is usually backward compatible with the older 1.1, but it’s possible that a USB 2.0 device could refuse to work on a USB 1.1 controller or external hub, so check to see if there’s a compatibility issue.

Assuming a firmware update is available, you may need access to a USB 2.0-equipped computer to apply it. Check the manufacturer’s Web site for information on using your USB 2.0 device in a USB 1.1 system.

Configurations for add-on USB controllers
Check the Windows Device Manager to see if the USB controller is recognized or is experiencing a conflict.

  • For Windows 2000:
    Click Start, Programs, Control Panel, System. Then choose the Hardware tab, and then click the Device Manager button.
  • ForWindows XP:
    Click Start, Control Panel, select the Systems applet, click the Hardware tab, and then click the Device Manager button.

The Device Manager will likely refer to the USB controller as a USB Root Hub, USB Controller, or USB Bridge. The usual suspects of IRQ addresses and memory address conflicts are the first things to check. PCI devices shouldn’t have many problems, being Plug and Play, but EISA cards may require more adjustment.

If the hardware appears to work, reinstall the drivers. If that fails to resolve the problem, relocate the card to another slot in case a master/slave configuration error is occurring.

Integrated USB controller settings
If you suspect the trouble is with your USB controller settings, check the Device Manager for a conflict. Depending upon how well integrated the controller is with Windows, you may be able to adjust the IRQ or memory address settings from the Device Manager.

Next, try rebooting your computer and entering the BIOS configuration. USB settings are usually listed in the “peripherals” section. You’ll need to check for an entry marked “USB Controller” that is off or inactive. If this entry is already active, check the IRQ and memory addresses. Use the Device Manager to ensure that no other device is using those settings. You may need to reboot a few times to find a valid IRQ/memory address combination that won’t conflict with other devices.

If the hardware settings are fine, reinstall the drivers.

  • USB keyboards
    When editing the BIOS, enable “DOS USB Keyboard Support.” Enabling this option will allow you to use a USB keyboard when booting a system with a boot disk.
  • Controller drivers
    Check the motherboard manufacturer’s web site for driver updates. Many motherboard suppliers release driver combinations that include a number of hardware drivers. Confirm that you have the latest driver installed. Some operating systems also provide drivers, so make sure you have the latest available software patch as well.

Power management
Most computers have some form of sleep mode connected with the screensaver. A controller is not harmed when an energy setting kicks and eliminates its power. However, the OS may fail to power up the controller again. You can eliminate this error by opening Power Options and disabling System Standby.

In Windows 2000, access the Power Options applet by clicking Start, Settings, Control Panel, Power Options.

In Windows XP, go to Start, Control Panel, Power Options. You’ll find the System Standby option on the Power Schemes tab, which opens by default.

For laptop computers, you shouldn’t disable the power management permanently. If the manufacturer doesn’t have a patch for the laptop, consider switching to non-USB devices when possible. You could also create two profiles for users: a portable profile with power management enabled and a desktop profile with power management disabled.

Excessive loads on the bus can also cause power problems. The USB controller can power USB devices. Small devices like your mouse and keyboard aren’t a significant drain, but larger devices, such as scanners, hard drives, web cams, and speakers can draw considerable power. You might be able to eliminate the problem by spreading the power-hungry devices across multiple root hubs. Otherwise, acquire a good self-powered external USB hub.

Inexpensive external hubs sometimes fail to meet the USB power specifications and subsequently cause all devices on the hub to fail. Upgrading to a USB hub that supplies more power solves this kind of problem.

USB device drivers
The ability to hot-swap USB devices is a great feature, but it relies on a somewhat oversimplified set of all-purpose drivers. Some devices may appear to be general-purpose devices when in fact they are not. You need to install the drivers before you connect the device to the PC. Sometimes you need to reboot to give the new drivers priority over the all-purpose drivers. Skipping the reboot will break the whole process.

If you think the new drivers aren’t receiving priority, completely uninstall the device in question. You may have to leave the device connected to uninstall it properly. At other times you may be able to remove a device’s drivers using Control Panel’s Add/Remove Programs applet, just as you would with other software.

Sometimes it’s necessary to upgrade a device’s firmware, which is basically a driver that runs on the peripheral. The more advanced the device, the more likely it is that the firmware can be upgraded. Your mouse probably doesn’t have any firmware upgrades. Scanners, hard disks, printers, optical disks, and other sophisticated peripherals likely have upgradeable firmware. Check the manufacturer’s site to make sure that you have the most recent update.

USB root hubs can each support up to 128 devices, but they can run out of bandwidth, depending on consumption rates. USB 1.1 is limited to 12 Mbps, not counting the bus management overhead. USB 2.0 has 480 Mbps with about 420 Mbpsavailable, so it can support more devices. Combine an Ethernet adapter, a printer, and an external CD-ROM or hard drive on a single USB controller, though, and the PC can quickly exhaust its capacity.

The only solution for bandwidth problems is to either stop using all the devices simultaneously or distribute the load. Make sure you put devices that will always see use, like Ethernet adapters and USB speakers, on different root hubs. You may need to get additional USB controllers, which are inexpensive, typically costing less than $40.

CD drive or DVD drive is missing in Windows XP

February 23rd, 2010 2 comments

Q. Help, my CD drive or DVD drive is missing?

A. I am taking this to mean your CD/DVD drive is not recognized, so you can’t play a CD or DVD.

You probably have either corrupted or deleted Windows registry entries. To solve this problem, you need to use the Registry Editor. ***Note: By using Registry Editor, you are modifying the registry. Serious problems might occur if you modify the registry incorrectly. Make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. For more information about how to back up and restore the registry, click here to read the article in the Microsoft Knowledge Base.

  1. Click Start, and then click Run.
  2. In the Open box, type regedit, and then click OK.
  3. In the navigation pane, locate and then click the following registry subkey:
  4. In the right pane, click UpperFilters.
    *** Note – You may also see an UpperFilters.bak registry entry. You do not have to remove that entry. Click UpperFilters only. If you do not see the UpperFilters registry entry, you still might have to remove the LowerFilters registry entry. To do this, go to step 7.
  5. On the Edit menu, click Delete.
  6. When you are prompted to confirm the deletion, click Yes.
  7. In the right pane, click LowerFilters.
    *** Note – If you do not see the LowerFilters registry entry, unfortunately this content cannot help you any further. Try contacting Microsoft for additional support.
  8. On the Edit menu, click Delete.
  9. When you are prompted to confirm the deletion, click Yes.
  10. Exit Registry Editor.
  11. Restart the computer.
  12. Click Start, click My Computer, and then see whether the drive is listed.

If you still can’t play or access a CD or DVD at this point, next try to reinstall the programs. If that doesn’t work, check to see if there are updates available at the manufacturer’s website. Some examples of programs that might be affected are:

  • iTunes software by Apple
  • Nero software by Nero Inc
  • Roxio Creator software by Sonic Solutions
  • Zune software by Microsoft

Additionally, you  can try to remove and reinstall the device drivers.

Do the following to remove and reinstall the device drivers:

  1. Click Start, and then click Control Panel.
  2. Click System and Maintenance, and then click System,
  3. On the Hardware tab, click Device Manager. If you are prompted for an administrator password or for a confirmation, type the password, or click Allow.
  4. In Device Manager, expand DVD/CD-ROM drives, right-click the CD and DVD devices, and then click Uninstall.
  5. When you are prompted to confirm that you want to remove the device, click OK.
  6. Restart the computer.

After the computer restarts, the drivers should be automatically installed.

Repairing Common Printer Problems

February 8th, 2010 No comments

Printer Cable:

One of the most common sources of printing problems is the printer cable. Normal wear and tear can damage one or more of the wires or pins in the connectors of your cable.

Cable problems simple to diagnose and correct. The fastest way to troubleshoot a cable with no obvious defects is to substitute a known good cable and see if the problem goes away. Or, you can place your questionable cable on a system that is having no problems, to see if your problems follow the cable.

Printer driver problems:

Another common printer problem is that your drivers are defective or out of date. You might even have the wrong one. This can result in all sorts of strange gibberish on the printed page. If you selected the wrong printer driver for the printer you are trying to use, you may need to purge the print jobs that are hung up in the spooler as well as reset the printer to remove any bad data that remains in its buffer.

It’s also possible that you have the correct printer driver but that it isn’t configured properly for the amount of RAM installed in your printer. If the driver is set for more RAM than the printer actually has, an overflow can occur. This might go unnoticed for a long time. It may appear only when you have a large print job or pages with lots of graphics.

Sometimes there are known issues with a printer driver that crop up only under certain circumstances. Make sure that you have the latest printer drivers for your operating system and printer installed. (To do this, check the manufacturer’s web site.)

Whenever you install a printer driver, make sure that all of the setting options are correct for your individual printer. This not only includes the RAM settings, but also settings like the source tray for the paper, the paper size and orientation, the timeout settings, and the print resolution.

Port Type
Another problem might be that your parallel port settings are incorrect in your CMOS setup. (Assuming that the parallel port is integrated on the motherboard.) First, see if Windows is giving any indication of a problem in Device Manager. To do this, click Start, Settings, Control Panel, and then double-click on the System icon. Now select the Device Manager tab. If there is a problem with the on-board parallel port settings, you will see a flag on the device, indicating a discrepancy. Highlight the parallel port and click Properties to view the device status. Next, click Resources to check out any resource conflicts.

It’s possible that when you last installed a component, you created a resource conflict that didn’t appear until later when you tried to print. If a conflict is indicated, try changing the resources that the offending device is using.

Testing the parallel port
Diagnostic software such as CheckIt or Norton Utilities can test the integrity of your port by using a loop-back plug attached to your parallel port. This type of test can also be performed on your serial ports. Make sure that you use a loop-back plug compatible with the testing software.

The loop-back plug test may not find every parallel port problem, but if it does indicate a problem, it’s probably accurate.

If you find a bad parallel port on a motherboard with integrated peripherals, you can disable the port in the CMOS Setup and install an add-on parallel port if you have an unused ISA slot. But check prices before you do this. You may be able to replace your motherboard with a new one for very little more than the cost of a new parallel port card.

Check the CMOS
If you find no resource conflicts, try changing the port type in the CMOS. Run the CMOS Setup program, open the Integrated Peripherals menu, and select the parallel port type settings. Press [F1] to view the default setting. If the default setting isn’t specified, try changing the mode to the default. You can also try setting to another value the memory address that the port is using. Start with the default setting and then restart the computer and try printing again. Windows will probably find what it considers new hardware and install the proper software during the start up process. Note: This is the process I followed on my computer. However, since every CMOS is different, your system may require you to change the port type in a different manner. Documentation may accompany your computer or motherboard (if it was custom built).

There are a lot of things that can go wrong with a printer. If you’ve eliminated all other possibilities and have decided that the printer is the culprit, consult the manual that came with your printer for user-serviceable items.

The new generation of inkjet printers has the capability of printing at a very high resolution. To achieve this resolution, you must choose from a variety of high-quality papers available. If you’re using standard quality inkjet paper, there is no benefit from choosing a very high resolution. The print speed will be greatly influenced by the resolution you select.

Don’t try to use the paper designed for an ink jet printer in your laser printer. This paper is not compatible with the high temperatures present in a laser printer.

If your laser printer has begun to print pages with some of the areas of the page appearing lighter than the rest, your toner cartridge may be a little low on toner. To get the maximum life from a toner cartridge, make sure that the remaining toner is evenly distributed in the cartridge. Do this by removing the cartridge from the printer and, while holding it in the same orientation that it rests in when installed, gently rock it back and forth, tilting it about 45 degrees in each direction. The object is to make toner available over the whole width of the drum. Be careful not to shake the cartridge too vigorously.

While you have the printer open and the cartridge removed, take the time to clean it out. Follow the directions in the owner’s manual carefully so as to not damage anything.