A previous post described how to determine the real age of a computer by looking at the power-on time instead of the date of manufacture. A related question that is frequently asked is how long will a computer last? Based on our experience and research, we have itemized the lifespan and failure modes of each individual component in a computer that can be replaced.
While the lifespan of a computer could be decided by the first component to fail, this is the most expensive and conservative approach to determine lifespan. Desktop computers have at least 5 different components, and the components each have their own lifespan that ranges from 10,000 to 50,000 hours or more.
We consider 50,000 hours to be the end-of-life range for most computers, since it represents almost 6 years of continuous operation. Given the pace of innovation, with storage and speed doubling every 18 months (based on Moore’s Law) any computer is worth replacing after 50,000 hours of usage.
We analyzed the return rate of failed components, comparing our return rate with the overall return rate of 20 other computer resellers from the same supplier. We found that our lifetime return rate for components was 5%, compared to 2.5% for everyone else. We believe our higher return rate is due to the 100% testing we perform on all RAM and other components. This also could mean that while 2.5% of all components fail and require replacement, another 2.5% of components that are failing remain undiagnosed and require testing.
RAM memory is very reliable with no moving parts, and easily tested with pass/fail diagnostics. Lifespans are considered unlimited, surpassing 50,000 power-on hours.
Processors are more reliable than RAM because they include a heat-sink and fan to promote cooling, and are the least likely component to fail in a computer. Lifespans are considered unlimited, surpassing 50,000 power-on hours. Most processors include an internal temperature sensor, so that they will shutdown or restart the computer if they overheat due to fan failure.
CPU heat-sink fans are a significant problem in many systems. While the fans that are included with Intel processors are extremely reliable, many computers use third party fans that are noisy or less reliable. Genuine Intel fans with ball bearings will run reliably past 50,000 hours, while third-party sleeve bearing fans will begin to fail after 10,000 power-on hours. CPU fans should be checked and cleaned with compressed air annually to eliminate the accumulated dust that leads to overheating.
Desktop and Server Motherboards most frequently fail due to bad electrolytic capacitors, so they need to be checked visually once a year for the early signs of electrolytic capacitor failure (cracking, bulging, leaking.)
Some models of motherboards have shown capacitor failure after only 2 years, while others show failure after 3-5 years. We have also seen motherboards that are more than 10 years old with perfect capacitors. All motherboards rely on capacitors, and they can have from ten to fifty capacitors.
Laptop Motherboards most frequently fail due to bad video chips. Both Dell and HP have had serious problems with laptops failing due to bad nVidia video chips. While laptop motherboards also have many capacitors, due to the miniature size and low voltage, they almost never include the failure prone electrolytic capacitors that are seen on desktop motherboards. Instead, laptop motherboards use miniature solid state metal capacitors that are extremely reliable.
Power supplies have spinning fans and many electrolytic capacitors. Lower quality sleeve bearing fans will become noisy after 10,000 power-on hours, while better quality ball bearing fans will last up to 50,000 hours. Larger 120mm fans run at a lower RPM than smaller 80mm fans, and the lower RPM increases reliability.
Failing fans inside power supplies are rarely replaced; instead, the entire power supply is replaced when the fan becomes noisy or fails to spin fast enough to cool the power supply.
Diagnosing capacitor failure in power supplies is practically impossible, since power supplies are completely shielded inside a metal box. This makes visual inspection of failed capacitors impractical. Typically, capacitor failure inside power supplies leads to power-on failure for the entire computer.
Since power supplies are a low cost item that requires no software configuration, they are fast and simple to replace. Not all computer manufacturers use standard power supplies, so when a computer with a non-standard size power supply fails it may require replacing the entire computer. Non-standard power supplies are typically seen in slim or mini size computers, while mid-tower computers usually have replaceable standard size power supplies.
Since 2009, all of the computers we assemble utilize ATX 2.2 power supplies with 120-mm ball bearing internal fans. These are the quietest and most reliable power supplies available. We use the same top quality power supplies when replacing failed power supplies in other manufacturers machines.
The lifespan of power supplies can be extended by cleaning them annually with compressed air. This removes the dust that accumulates inside the power supply, which reduces the cooling effectiveness of the fans.
Hard drives are the most complex component in a computer. The common hard drive has a circuit board that can overheat and burnout, magnetic discs that can fail to read or write, and a high speed drive motor that can wear out and fail.
Most hard drive failures occur due to problems with reliably reading or writing to the discs. Since hard drives include incredibly sophisticated error correction capabilities, most errors are managed by the drive to prevent failure. These errors can be detected and monitored using diagnostic software that retrieves the stored error history of the drive.
For hard drives below 80gb in size, they typically have ball-bearing motors that are limited to 5400-rpm and will wear out and increasingly fail after 20,000 power-on hours. Almost all hard drives above 80gb use silent fluid dynamic bearings that are more reliable and will last beyond 50,000 hours.
The manufacturer guidelines for hard drives generally predict a power-on lifespan of 20,000 hours for 2.5″ laptop drives and up to 50,000 power-on hours for 3.5″ desktop drives. We generally recommend replacing any hard drive that has more than 40,000 power-on hours.
SSD storage drives are new in 2011. SSD’s are inherently more reliable since they have no moving parts to wear out. However, the NAND flash memory inside the SSD has a limited write repeatability. Typically, each 512-byte data block is limited to an estimated 10,000 writes before it may begin to fail or stop saving new data.
For example, a 120gb SSD may be rated by the manufacturer for 64TB (terabytes) of lifetime data writes, which could be the equivalent of 5 to 50 years of daily usage. SSD’s do not have a read limit and have excellent retention, rated at up to 100 years.
CD and DVD drives are another motor driven mechnical component with a limited lifespan. Even though a CD drive may be used infrequently, they frequently develop tray problems that prevent the tray from ejecting. As a low-cost component, they are easily replaced.
CRT monitors rely on phosphor coated glass, so they become gradually dimmer with age. Most CRT monitors reduce to 50% brightness after 5-7 years of daily usage, equivalent to 10,000 or more hours.
LCD monitors with CCFL backlights tend to fail after 5 years or 10,000 hours, with the power inverter the most likely component to fail. The CCFL (fluorescent) backlight bulb in an LCD monitor will also become pink and dim as it ages; there is no repair or replacement method for bulbs. For laptops, LCD panels and inverters are easily replaced and readily available. However, for desktop LCD’s, there are no repair parts available.
LCD monitors with LED backlights are the newest technology and represent the highest quality and reliability. Since the LED backlight doesn’t need a high voltage inverter, this eliminates the most frequently failed component. LED bulbs are also very reliable, lasting beyond 50,000 hours. For monitors that are used 8 hours a day, an LED backlit LCD panel can last up to 25 years.
Laptop batteries have the shortest working lifespan of any computer component. A typical laptop battery will provide 1-2 hours of run-time, and requires 2-4 hours for a full charge cycle. Typical Lithium-Ion laptop batteries are limited to 300-500 charge cycles, resulting in a lifetime run-time limit of 500-1000 hours. Given that a laptop can be used up to 2000 hours per year or more, laptop batteries can require annual replacement. To accurately determine the number of charge cycles, battery diagnostic software must be installed to report on the actual battery operation.
Lithium coin batteries: Most motherboards have a socketed 3-volt Lithium coin battery that provides power to the BIOS (Basic Input Output System) CMOS (complimentary metal-oxide semi-conductor) chip. The CMOS chip stores BIOS configuration settings for the hardware. These batteries are rated for up to 10 years or 100,000 hours of continuous operation. They are inexpensive and easily replaced. Most computers will display a “CMOS error, battery power lost” on startup when the Lithium coin battery can no longer provide enough power for the CMOS chip to save the settings. The most common replacement battery is the CR-2023, widely available in stores for less than five dollars. We stock new replacement batteries for $2.