 Read enough articles regarding working on a PC’s interior, and you’ll notice a common trait. No matter the project—be it replacing a graphics card, installing a hard drive, or removing built-up dust—nearly every article includes a warning to protect against built-up static electricity before working inside a PC. A second warning nearly always follows that failing to do so could damage your PC’s components.
Where these articles differ is in how they tell you to ground yourself. To that end, we offer this authoritative solution for grounding oneself of ESD (electrostatic discharge). To help select our method, we surveyed 10 employees at nine mainstream and custom PC, PSU (power supply unit), and case manufacturers, asking each why grounding is imperative and what method they use. You can read in-depth answers from each builder at Smart Computing’s Web site, www.smartcomputing.com.
 Reasons To Ground
Although methods differ, why you should ground yourself is pretty much universally agreed on. The components inside a PC, including CPUs, graphics cards, and RAM, are extremely sensitive to ESD, which the human body can discharge. A discharge to an ESD-sensitive component can damage or destroy it. System memory errors, freezes, and BSODs (Blue Screens Of Death) are a few issues traceable to grounding-related incidents.
“Any time you touch an ESD-sensitive component without properly grounding yourself, you run the risk of creating hardware problems where there were none before,” says Ben Smelley, Velocity Micro product development manager. “CPUs, motherboards, memory, and PCI/PCI-E [Peripheral Component Interconnect/PCI Express] cards are the most vulnerable, but power supplies, optical drives, hard drives, and anything else are still at risk.”
Thomas Szolyga of Voodoo PC and HP’s Blackbird division describes the importance of grounding this way: “Consider winter in the Great White North when the relative humidity is 20% or less. Wearing rubber-soled shoes, drag your feet across the carpet until you get a really good static charge. With your PC plugged in, bring your finger close to the metal chassis. You will see a quarter-inch or more spark. That represents about 20,000 volts. The I/O [input/output] pads on a typical microprocessor are protected to about 5,000 volts. ’Nough said.”
   Matthew Petrie, a Falcon Northwest technician, says the common “zap” felt during a small ESD discharge takes 500 to 1,000 volts. “Through the course of a normal day, most people will unknowingly experience a large number of undetected static discharges of less than 500 volts. It’s important to note that these smaller, silent discharges can damage sensitive electronic components. You don’t have to see, hear, or feel the discharge to do damage.”
Greg Parlier, Voodoo PC manufacturing program manager, says photographs he’s seen at the microscopic level from motherboard, sound card, and PCB [printed circuit board] makers show, “It is very clear that an over-current situation caused the failure. . . .” Parlier adds, “I have seen through research that even if the component does not fail immediately, it will fail early on because the PN [p-type and n-type semiconductors] junction has been weakened by ESD.”
Ways To Ground
Pro builders understandably go to extremes to prevent grounding mishaps, using such measures as antistatic, concrete, and rubber flooring; antistatic mats and floor grounders for shoes; antistatic tabletops; and antistatic wrist, ankle, and foot straps. Velocity Micro’s Smelley says, “A key element commonly disregarded . . . is humidity. Dry atmospheres lend themselves to allowing electrostatic energy to be accumulated. Adding a humidifier to a room or production facility is extremely beneficial in ensuring ESD safety.”
For home users without such resources, three prevailing approaches to grounding include:
• Unplugging the PC’s power cord from the electrical outlet and touching a nonpainted metal portion of the PC’s case
• Unplugging the cord and wearing an antistatic wrist wrap
• Leaving the cord plugged in and either touching a nonpainted metal portion of the case or wearing an antistatic wrist wrap
All but one builder we asked uses antistatic products. For home users, antistatic wrist wraps are the least inexpensive and most convenient option. Wraps start as low as $3.50 at many resellers. Six builders we asked recommended unplugging the power cord, while three recommended leaving it plugged in. James Cash, Alienware’s senior assembly supervisor, favors unplugging because, "There are several incidents that can occur when working on a unit while it's plugged in. Components can be damaged if a screw is dropped inside the machine and the component shorts out. Also, you could be injured by touching a fan or burned by touching a copper heatsink after it has been running for a few minutes.”
Conversely, Parlier recommends leaving the cord plugged in. “Utilizing the case as a grounding point is only effective if the case is grounded. The ground is provided through the third prong of the power cord. Disconnecting the power cord removes the ground and greatly reduces the case’s potential for absorbing static electricity. Or, more accurately, it can only absorb a finite amount of static electricity, as it cannot pass it through to the ground.” George Yang, an iBuyPower.com product engineer, also prefers the cord plugged in but adds, “You can leave it plugged in as long as you remember to switch off the power supply. By turning off the power switch on the PSU, the case will still be grounded through the power supply and ground line of the power cord.”
The Smart Computing Way
Of the three primary grounding methods, we recommend wearing an antistatic wrist wrap and unplugging the power cord. Beyond being an inexpensive option, wearing an antistatic wrist wrap ensures you’re grounded at all times, substantially reducing the risk of damaging a component vs. touching a metal part of the case. Antistatic wrist wraps come in corded and cordless varieties, though cordless wraps are typically more expensive. Using a corded wrap involves strapping the wrap around your wrist and attaching a clamp to the case according to the strap’s instructions.
Before diving into your PC’s interior, it’s good practice to back up your data first. Additionally, wash your hands with soap and water to help discharge static electricity from your body. Avoid working on carpeted flooring or thick rugs. Instead, use a room with tiled, wooden, or concrete flooring if possible. Also, avoid wearing clothing that easily builds up static electricity and place the PC on a clean tile or wood table. Finally, turn the PSU’s power switch off.
If you opt against wearing a wrist wrap, plant your feet firmly on the ground and avoid shuffling them while working. Before and frequently during your work, touch a nonpainted metal part of the case, preferably an area far from the components.
Stay Grounded
As Josh Smith, CEO of Biohazard Computer Systems, points out, wearing antistatic wrist wraps or using other antistatic products may seem akin to “a pocket protector” or “über geekdom,” but the effort is worth it. “Some choose to follow antistatic policies, and others do not, thinking they are too cool to be bothered with them,” Smith says. “I can tell you no one feels too cool when he hears a little static ‘crack’ . . . and his $600 video card doesn’t work anymore. It may be remote that you actually fry a component statically, but I have seen it happen, and when it’s so easy to prevent, it’s hard not to feel [silly] afterward.”
by Blaine Flamig
Get Grounded
Grounding yourself before opening your computer (and while you work inside the PC) prevents ESDs (electrostatic discharges) that can cause permanent damage to the PC’s hardware. To find the best grounding methods, we talked to the pros. Here are our questions and their responses.
Smart Computing:
A) Why is grounding yourself before working on any computer-related task important? What risks do you run if you don’t?
B) There seems to be three prevailing thoughts regarding what to do with the PC’s power cord. Which method do you recommend and why?
1. Unplug it and touch a metal portion of the PC’s case
2. Unplug it and wear an antistatic wrist wrap
3. Leave it plugged in and either touch a metal portion of the case or wear a wrist wrap
C) Can you relate any first- or second-hand incidents involving improper grounding?
James Cash, senior assembly supervisor
Alienware
www.alienware.com
A) It’s very important to ground yourself because you run the risk of damaging hardware. Electrostatic charges build up in our bodies by everyday actions, such as walking across a carpeted floor or getting up out of a chair. If you’re not grounded, you could receive an uncomfortable jolt and possibly short out a component.
B) I would recommend unplugging the unit and wearing a wrist strap if possible. There are several incidents that can occur when working on a unit while it’s plugged in. Components can be damaged if a screw is dropped inside the machine and the component shorts out. Also, you could be injured by touching a fan or burned by touching a copper heatsink after it has been running for a few minutes.
Josh Smith, CEO
Biohazard Computer Systems
www.biohazard-computers.com
A) Grounding is important with regards to dealing with computer hardware, as these items are sensitive to electrostatic shock—especially such items as PCB [printed circuit board] boards, such as video cards, sounds cards, motherboards, etc. The primary risk is to the hardware itself, in that a small static discharge can damage the hardware component rendering it unstable or nonfunctional.
B) Personally, we unplug our systems when working on them. The wrist straps work well (especially the cordless varieties), as you don’t have to keep reminding yourself to discharge before touching components.
C) For some odd reason, it seems to be that many computer enthusiasts, as well as those in the industry, tend to take a negative view on wrist straps, etc. Perhaps it is a mental link to a pocket protector and über geekdom. Some choose to follow antistatic policies, and others do not, thinking they are too cool to be bothered with them. I can tell you, no one feels too cool when they hear a little static ‘crack’ and all of a sudden, his $600 video card doesn’t work anymore. It may be remote that you actually fry a component statically, but I have seen it happen, and when it’s so easy to prevent, it’s hard not to feel [silly] afterward.
Chuck Morris, system engineer
Vigor Gaming Computer
www.vigorgaming.com
A) Grounding yourself is important when working with computers because DC power supplies produce high amperage currents. This high amperage makes possible electrocution from a computer far more dangerous than being zapped while tinkering with an electrical socket in your home. Human dangers associated with improper grounding range from minor injury to death, while system dangers are usually limited to the complete ceasatione to function correctly. Improperly grounding a motherboard, for instance, can fry vital regulation components that will prevent the board from working properly. This can cause hundreds of dollars (thousands these days) of damage in a fraction of a second.
B) We always recommend unplugging the power cord from the power supply. We also recommend wearing an antistatic wrist strap when tinkering with the computer, but oftentimes, we know that this is not a possibility. In the event a customer or whoever is not in possession of an antistatic wrist strap, we advise them to touch a portion of the computer case, usually near the front drive bays, farther away from very costly components.
C) It used to be very common for especially sensitive components like modems to stop working at even the slightest hint of ESD. Sometimes, this could be fixed by unplugging power to the board completely, but oftentimes, it made the modem stop working entirely. This was the bane of many tech support personnel’s existence for quite a while.
Matthew Petrie, support technician
Falcon Northwest
www.falcon-nw.com
A) Everyday tasks involving movement result in a natural buildup of static electricity. Properly grounding yourself discharges this static buildup and allows you to handle static-sensitive electronic devices safely. Failure to ground yourself properly before handling an electronic device can result in a discharge of this built-up static electricity into the device. Electrostatic discharge into an electronic device can cause immediate and total failure, reduce the life of the affected device, or result in intermittent and unreliable behavior.
Static electricity is characterized by high voltage and low amperage. It takes a buildup of at least 500 to 1,000 volts in order to result in a small detectable discharge (the oh-so-common ‘zap’ you feel). A higher buildup will result in a more powerful discharge. Through the course of a normal day, most people will unknowingly experience a large number of undetected static discharges of less than 500 volts. It’s important to note that these smaller, ‘silent’ discharges can damage sensitive electronic components. You don’t have to see, hear, or feel the discharge to do damage.
Electrostatic discharge into an electronic device results in a high-voltage signal passing through the circuits and electrical pathways of the device. As most devices are designed for an electrical signal of 12V or less, this large excess of voltage causes havoc on the delicate, microscopic architecture of today’s electronics.
Apart from the minor discomfort of an electrostatic discharge, it is harmless to your personal well-being. The largest risk health-wise would involve the discharge of a static charge in a combustible environment (for example, the discharge could result in an explosion of flammable gases).
B) I would recommend the third option, leave it plugged in and either touch the case or wear a wrist strap. Utilizing the case as a grounding point is only effective if the case is grounded. The ground is provided through the third prong of the power cord. Disconnecting the power cord removes the ground and greatly reduces the case’s potential for absorbing static electricity. Or, more accurately, it can only absorb a finite amount of static electricity, as it cannot pass it through to the ground.
I would add that it is important to turn off the power supply before performing any work on a PC’s interior. Most modern power supplies will include an on/off toggle switch on the rear of the power supply. Assuming that the power supply does not have such an on/off switch, it would be important to disconnect the power cord in order to cut power to the system. In this instance, utilizing a grounding point other than the case would be appropriate.
C) I’ve killed one of my routers with an electrostatic discharge. After connecting a new Ethernet cable to the router, I picked up the opposing end of the Ethernet cable to connect to the PC. Upon picking up the cable, my fingertips brushed the connector, and I felt a zap as the discharge entered the cable. Sure enough, the charge traveled along the cable and into the router. The router has been dead as a doornail ever since.
This experience does bring up a good point: A cable attached to a device can be a vulnerable path for static electricity. On a similar note, the contacts of electronic components are a direct pathway to the heart of the device and will generally be much more sensitive to static discharge. Avoid handling the pins of device cables or contacts of an electronic device whenever possible.
George Yang, product engineer
IBuyPower.com
www.ibuypower.com
A) You need to ground yourself to discharge your body of static electricity. Just walking on carpet will build up static electricity, and it is very detrimental to electronic components. Static electricity is a build up of very high voltage—voltage that can go up into the thousands, but there is very little current, so it usually will not do any harm to a person’s body. However, exposed electrical components on video cards, motherboards, hard drives, etc. can get damaged from these high voltages.
The danger to the person is when you have power running through the system and if it or you are not properly grounded, the person may become the path to ground. So if you handle the system incorrectly with power running, you may get a very high power shock or even electrocuted. Of course, you should never work on a system with power running anyway.
B) I would recommend unplugging the power cord and wearing an antistatic wrist strap. However, you can leave it plugged in as long as you remember to switch off the power supply. By turning off the power switch on the PSU, the case will still be grounded through the power supply and ground line of the power cord. Since most home users do not have antistatic wrist straps, this would be the best option for home users.
Tony Ou, product manager
SilverStone Technology
www.silverstonetek.com
A) Grounding yourself before working inside the computer case can help to reduce the chances of shorting and damaging more sensitive components via static electricity.
B) We suggest unplugging the power cord at all times for working on any computer.
C) Dead motherboards appear to be the most common casualties of static electricity damages.
Ben Smelley, product development manager
Velocity Micro
www.velocitymicro.com
A) Any time you touch an ESD-sensitive component without properly grounding yourself, you run the risk of creating hardware problems where there were none before—from as little as making something sporadically malfunction without any rhyme or reason all the way to completely killing a piece of hardware. CPUs, motherboards, memory, and PCI/PCI-E [Peripheral Component Interconnect/PCI Express] cards are the most vulnerable, but power supplies, optical drives, hard drives, and anything else are still at risk. Grounding yourself is important to mitigate the risks outlined previously. It is also possible that if you send an electrostatic charge to a component in the computer while it is turned on, it could cause the power supply to short, and in rare cases, a fire could be created at the power supply or wall socket where the computer is plugged in.
B) Method 3. By leaving the power cord plugged in (which inherently has a ground pin going to the wall), you keep the components grounded, as well—at least anything that has a direct link to the power supply. This is half the battle. The other half is ensuring you do not carry any electrostatic charge to the components [because the components] being grounded will have no affect at that point, so wear your wrist strap, use your antistatic/grounded mat, and make sure you have properly discharged any static electricity before touching any components. The most important thing to remember with this philosophy is that if the power cord is still plugged in, due to the nature of ATX power supplies, there will be current running to the computer. To eliminate this potential threat, be sure to flip the power switch. This is not the computer’s on/off button, rather the switch on the power supply that’s typically located near where the power cord plugs into the power supply.
C) One of the first experiences I remember having with ESD in electronics, computers specifically, came about 15 years ago. I was watching someone replace a power supply—this is back in the AT PSU days. He walked across the carpeted room to get a cup of coffee, walked back, and noticed the power to his floppy drive was only partially seated. In the process of reaching in the case to adjust, he grazed something on the motherboard, sent an electrostatic charge to it, which in turn blew the power supply, the outlet where the computer was plugged in, and the power to the entire building. Because of this, every component in the case was dead, except—ironically enough—the floppy drive.
Greg Parlier, manufacturing program manager
Voodoo PC
www.voodoopc.com
A) When we perform the normal movements necessary to manufacture a product, such as walking, bending, and lifting, our bodies tend to acquire a static charge. Static charges accumulate on the surfaces of nongrounded conductors (human body) and on nonconductive (isolative) surfaces. They cannot move because there is no path to ground. If a component comes in contact with a ground path, the static charge is suddenly transferred to ground. If the path of discharge is across the component, it could be damaged. If you don’t ground yourself, a sensitive electronic part will either be destroyed or become a latent failure (wounded) waiting for the final curtain to fall on its expected performance. ESD damage costs both dollars and dissatisfied customers.
B) Static charge is released because of the difference in electrical potential between the chassis and body. Most instructions with new components say to wear a grounding strap or touch the chassis to discharge any built-up static charge. In my opinion, leaving the power cord plugged in is in fact the best source to redirect the build-up, however, the risk of electric shock (zap) can cause injury to yourself and other components and is more the reason for this warning. So to be safe, unplug the cord and ground yourself. That’s why I would recommend No. 3.
C) I have worked in the computer manufacturing environment for many years and cannot speak to a specific situation I can relate to you but have worked with many component manufacturers for failure analysis, and the most common item for component failure is from ESD shock. I have seen many pictures supplied by motherboard, sound card, and other PCB manufacturers that show this if you look at a cutaway at the microscopic level. It is very clear that an over-current situation caused the failure from the pictures I have seen. In addition to this, I have seen through research that even if the component does not fail immediately, that if will fail early on because the PN [p-type and n-type semiconductors] junction has been weakened by ESD.
Thomas Szolyga, engineer
Voodoo PC/ HP Blackbird Division
www.hp.com
A) To answer the question, consider winter in the Great White North when the relative humidity is 20% or less. Wearing rubber-soled shoes, drag your feet across the carpet until you get a really good static charge. With your PC plugged in, bring your finger close to metal chassis. You will see a quarter-inch or more spark. That represents about 20,000 volts. The I/O [input/output] pads on a typical microprocessor are protected to about 5,000 volts. ‘Nough said.
C) Here is an interesting problem with PC power supplies and proper grounding. Consider a situation where a consumer lives in a home built before 1955. These homes used two-wire AC cabling instead of the three-wire used today. Each outlet has only two wires: AC hot and AC neutral; there is no ground. In such a home, when the outlet breaks, it is replaced with a three-wire outlet, since two-wire outlets are no longer available. The third wire ground is left unconnected. In a PC power supply, there is a small capacitor connected from each side of the AC circuit to the AC third wire ground. In the chassis, the AC third wire ground is connected to the chassis. All of this is to reduce RFI [radio frequency interference] emissions. If the ground prong in the PC’s power cord is not connected to ground, the capacitors will slowly charge up the chassis to half the line voltage. Touching the chassis while holding a true earth ground will produce a momentary shock. You can duplicate the experiment by using a three-prong to two-prong adapter and not connecting the ground lead from the adapter. A high impedance volt meter will measure 62.5V between the metal chassis and the AC outlet third prong.
Everardo Parra, product manager
War Machine PC
www.projectwarmachine.com
A) Grounding yourself before performing a computer-related task is important because some PC components are very sensitive and can be damaged very easily.
B) I unplug the power cord and touch a portion of the case. I have not tested one method vs. the others; it’s just my preference, and I have had good experience with this method.
C) I would have to say system RAM and graphics cards are the most fragile components from my experience. Years ago, a friend of mine was building a PC (AMD Socket A) in his living room. We had the parts laid out on the floor. The floor was carpet, and he asked one of my friends to pass him the DDR [double-data-rate] RAM. Our friend walked a few steps and bent over to pick up the memory, and we heard a small ‘pop’ when he grabbed a stick. This was value RAM and did not have heat spreaders. We did not notice any physical damage, but the system would not POST [power on self test] with that memory DIMM [dual in-line memory module] in the machine. From then on, we built our PCs in his garage with a cement floor and a rubber floor mat. |
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