How to check your desktop computer for failed capacitors

Is your desktop computer running slower than normal? Does it randomly or constantly freeze up or restart? Or maybe it doesn't boot to the operating system or even boot at all. If so, your computer could have a failed capacitor.

Every computer repair shop has their own set of standard procedures and we are no different. The very first thing we do when someone brings in a desktop computer is check for blown capacitors. With a quick visual inspection, we can spot a costly computer repair. And you can too. Here's how to inspect your desktop computer for failed capacitors.

Symptoms of bad capacitors

Now before you go and take your system apart, let's take a look at the symptoms of a failed capacitor. Does your computer have any of the following problems?

  • Runs slows
  • Randomly freezes up
  • Randomly / constantly restarts
  • Won't boot to an operating system
  • Won't start at all

If so, it might be worth the time to take a look inside your computer.

Types of capacitors

Visual differences between water based and polymer based electrolyte capacitors
Visual differences between water based and polymer based electrolyte capacitors

There are primarily two type of capacitors used on computer circuit boards (motherboards, graphics cards, etc.), water-based electrolyte and polymer-based electrolyte. The majority of failures I have seen are with water-based capacitors, but polymer-based do fail too, just not as often. During the years of 1999 thru 2007, millions of faulty water-based capacitors were produced by some Taiwanese manufacturers. The electrolyte will evaporate and turn into a gas, thus bulging the case, and in some cases, leaking.

Checking for bad capacitors

Top view of a row of failed capacitors
Top view of a row of failed capacitors
Side view of a failed capacitor
Side view of a failed capacitor

The following can be performed with the computer in-place, provided you have enough room. If not, you will have to move your computer to a location that does. Take a photo of where everything goes first, then completely disconnect all cables that attach to it.

  1. Power down your computer and
    • Remove the power cord from the back of the power supply (in-place inspection)
      or
    • Disconnect all cables (relocated inspection)
  2. Open the case.
  3. Remove any obstructions, like fan shrouds, so you can view the entire motherboard and other add-in cards.
  4. Using a flash light, visually inspect all capacitors on the circuit boards (motherboard, graphics card, etc.). You may need to physically remove some of the add-in cards to inspect them. Visual symptoms include:
    • Bulging or cracking of the vent on top
    • Casing sitting crooked on board as the base may be pushed out
    • Electrolyte that may have leaked out on to motherboard (rust colored)
    • Case is detached or missing

What to do if you find a bad capacitor

If you do find a bad capacitor, there are three (3) options. First thing, if your computer is still operable, backup your data ASAP (see links below). There are a lot of factors involved in deciding which option to choose, age of the system and cost being the two major ones.

  1. Repair the motherboard
    You can replace the bad capacitor yourself (see link below) or have a trained professional do it for you.
  2. Replace the motherboard
    EBay is a great place to find a refurbished motherboard.
  3. Replace the computer
    If you've been looking for an excuse to get a new computer, you just found one. Or maybe two or three.

For more information on failed capacitors:
Capacitor plague - Wikipedia

For more information on how to replace failed capacitors:
Recapping your own motherboard - Badcaps.net

For more information on how to backup your computer:
Windows XP Backup
Windows Vista Backup
Windows 7 Backup
Windows 8 Backup

A computer that randomly and frequently freezes up

When it comes to computer repair, you have to be a detective of sorts. And once in a while I come across a really good mystery. I recently got a HP M7360N in the shop that would randomly freeze-up in Windows XP when you moved the mouse. It would run perfectly fine in Safe Mode. Maybe a bad driver?

A check of the event logs yields absolutely nothing, not a single error. I check Device Manager and find the hard drive controller listed under the Unknown category, even though it is correctly identified as an Intel controller. I uninstall it inside Device Manager and then scan for hardware changes. The hard drive controller reinstalls back into the Unknown category.

The system is still freezing up randomly when the mouse is moved. I try a PS2 and USB mouse and got the same results with both. I disable all non-essential drivers and reboot with no change. I download the original and latest drivers for the system, trying all with no luck. Maybe a corrupt installation?

I create an image of the hard drive and then wipe it clean. Using the supplied recovery disks, I proceed to re-install the operating system and recovery partition. The system froze-up three times during reinstallation. But this time the hard drive controller is under the correct category, IDE ATA/ATAPI controllers. It's starting to look like a hardware issue.

I run a few DOS based utilities to test the memory, hard drive, etc. with no luck. I even try the HP recovery diagnostics. Every test I run tells me that there is nothing wrong with the hardware. Using the keyboard only in Windows, I am able to install another utility to test all of the motherboard components. I allow it to run for six hours and the system passes every test.

The BOIS is the next place I look and find it's a few versions older than what is currently available for download. I download and install the latest BIOS version and it still keeps freezing up randomly when the mouse is moved. I start searching the internet for clues.

After a few different search queries, I come across an article at Badcaps.net discussing symptoms of capacitor failure on motherboards, one being 'system randomly and frequently freezes'. I check the motherboard thoroughly and find no capacitors that look bad. I start checking the expansion (add-in) cards and all at once, the mystery was solved.

There on the graphics card was a bank of capacitors that the tops were swollen.

Top view of the graphics card showing the difference between a good and bad capacitors
Top view of the graphics card showing the difference between a good and bad capacitors.

Side view of the graphics card showing the difference between a good and bad capacitor
Side view of the graphics card showing the difference between a good and bad capacitor.

The movement of the mouse on screen was causing the graphics card to freeze-up. I re-assembled the system with a new graphics card and the issue was gone. Another computer repair mystery solved.

How to clean the dust out of your computer

Living in the desert, the one thing we have allot of is dust. Dust is a problem, since it can block up air vents, heat sinks and cooling fans inside of your computer. Not to mention that dust is a conductor of electricity. You should clean the inside and outside of your computer at least every three months, more often when you live in dusty areas (like Phoenix). I do it monthly, as my main system is in an open case (Antec Skeleton).

Let's start by turning off the computer and unplugging the power supply. Now, with the system de-energized, we can begin cleaning it. Since this can be messy, I recommend that you do this outdoors. This does mean disconnecting all attached devices / peripheral, but you won't be blowing the dust back into the surround area.

*** Note: As you clean your computer, check for cooling fans that spin freely. If you find one that does not move freely when you spray compressed air on it, it may have failed. ***

First, let's open up the case. If the front panel of your case can be removed safely, go ahead and remove it too. Using a can of compressed air or air compressor, lets start inside and work our way out.

Typical computer case with front and side panels removed
Typical case with front and side panels removed

Clean the CPU fan & heat sink fins
Clean the CPU fan & heat sink fins

Clean the vents and/or cooling fan on the power supply
Clean the vents and/or cooling fan on the power supply

If your system has a graphics card, clean the fan and/or heat sink
If your system has a graphics card, clean the fan and/or heat sink

Clean all heat sinks and open slots
Clean all heat sinks and open slots

Clean all case fans
Clean all case fans

Clean all openings in case and connection points
Clean all openings in case and connection points

Once the dust has settled, reassemble the case, re-attach all devices and you are all done.

When your motherboard does not save settings it may be time to replace the CMOS battery

At some point in time, your motherboard may forget the time and date or the onboard device settings. A Complementary Metal-Oxide-Semiconductor (CMOS) is used on the computer's motherboard to save the system settings (time and date, on-board devices, etc.). It uses an on-board battery to keep it powered when the system is turned off. The standard replacement is a CR2032 lithium battery.

Typical CMOS battery
A generic CR2032 lithium cell

Common indicators that the CMOS battery needs to be replaced

  • You start your computer and almost immediately get a message similar to this: System settings have changed Press F1 to resume, F2 to Setup.
  • You run your computer 24/7, only restarting for maintenance. You notice that the on-board clock is running slow and not keeping the correct time.

Replacing the CMOS battery

  1. With the system turned off, unplug the power cord.
  2. Open the computer case.
  3. Locate the CMOS battery.
    Typical CMOS battery location
  4. Press the battery release lever and the battery will pop up.
    CMOS battery release lever
    CMOS battery released
  5. Replace with a new battery.
  6. Close the computer case and plug it the power cord.

Migrating from a Palm TX to a Google Android

With the purchase of Palm by HP, I am reminded that the Palm Pilot is dead. For years I had been using a Palm Pilot, starting with a Vx, then a M505 and finally a TX. It was all of the applications available for the Palm OS platform that keep me there. So when my cellular phone provider, Verizon Wireless, had a great deal on a Google Android, I decided to go for it.

Palm TX & Google Android - Side by side (vertical view)
Palm TX and Google Android side by side (vertical and horizontal views)
Palm TX & Google Android - Side by side (horizontal view)

The first thing a had to look at was getting the same functionally from the Android as I did from the Palm. I started with the existing applications I used on the Palm. Sure enough, Dataviz, creators of Documents To Go had a version for the Android. It has almost all of the same functions as the Palm version.

Next was synchronizing Micorosoft Outlook with the Android. I was using the conduits in the Palm Desktop to sync with Outlook, so I had to look around to see what I could find. I came across CompanionLink, makers of DejaOffice. It has all of the same functions as the Palm conduits.

And last but not least, since the SD card in the Android appears as a removable disk in Windows 7, it is just a matter of synchronizing between the two. For this I am using SyncToy 2.1 from Microsoft to work just right for me.

Scott

Professional Service + Affordable Prices = Geeks in Phoenix

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