Common Problems with Power

1. Flickering Lights
2. Errors in Data Transmissions between Nodes
3. Unexplained Component Lockup
4. Premature Component Failure
5. Hard Drive Crashes
6. Corruption or Loss of Data in CMOS and Other EPROM Chips
7. System Devices Behave Erratically when too many are turned on
8. Frequently Aborted Modern Transfer
9. Wavering Monitor Screens
10. Disc Drive Write Errors

Problems with Power

Computers are sensitive to their power environment. Anyone who has ever had a computer toasted by a lightning strike or who has lost a morning’s work to a sudden blackout knows that all too well. But even with the increased awareness of the need to protect computers from power problems, many people still believe their vulnerability is limited to the occasional storm or utility outage. There are two unfortunate realities of the electronic age; the utility companies simply cannot provide the clean, consistent power demand by sensitive electronics, and you are responsible for the health and safe operation of your equipment.

In fact, studies suggest that the electrical environment in which most computers operate is a far "dirtier" place than we once realized. Final data from massive five-year survey of power quality in North America conducted by National Power Laboratory indicate that the average computer site is subject to 289 disruptive or destructive power disturbances per year. Moreover, the most noticeable types of problems-blackouts and lightning strikes-account for less than 12% of these events. Most are under- and over-voltage conditions and electromagnetic interference-disruptions that are nearly impossible to detect with the naked eye. A more recent study by IBM has showed that a typical computer is subject to more than 120 power problems per month. The effect of the power problems range from the subtle-Keyboard lockups, hardware degradation-to the dramatic data loss or burnt motherboards.

So how do you know if electrical glitches are disrupting or damaging your computer, short of investing a fortune in power monitoring equipment? Here are ten tell-tale signs of power trouble. While no single symptom is conclusive evidence of flaky power, if your computer suffers two or three symptoms regularly, you should probably look into an Uninterruptible Power System (UPS) or some other power protection device.

Symptom One: Flickering Lights

Like blackouts and lightning strikes, this is one sign that most people recognize as being power related. Flickering lights usually are a sign that your facility is experiencing split second outages or voltage sags. Unfortunately, there is often a tendency to dismiss these flickers as inconsequential; after all, they are over with literally in the blink of an eye.

Solution: Workstations or non-critical may be fine with level 3 UPS. It is recommended for servers and other critical equipment to use a level 9 UPS and a minimum of level 5 UPS. Need help with your selection? Contact Us.

Symptom Two: Errors in Data Transmission Between Nodes

While this is one of the most common problems LANs face, few network technicians recognize that power problems may be the cause. Actually, two different kinds of power aberrations can interfere with internode communications: ground loops and electromagnetic interference (EMI).

EMI consists of electrical impulses generated by noisy devices such as radio transmitters, fluorescent lights, and even computer power supplies. These impulses travel through the air, and a data cable can pick them up in the same way that an antenna picks up broadcast signals. These conducted EMI impulses create noise on the data cable, interfering with communication between workstations, servers, and other peripherals.

Solutions: Where possible, keep voltage differential from developing by plugging all devices into a single grounding point, such as a Level 5 or Level 9 UPS. Use data line surge suppressors to prevent impulses from reaching the computer. Run longer data cables through shielded, grounded metallic conduit to prevent EMI from reaching the cable. Keep cable runs away from noise generators-especially fluorescent lights. Need help with your selection? Contact Us.

Another common sign of power problems is the tendency of servers or workstations to freeze. While many factors can cause this sort of lockup, random system crashes are often a sign of low voltage sags or subcycle power failures have sapped your logic circuits of the voltage they need to operate properly. NPL and Bell Labs power quality data show that voltage sags are the most common type of power problem.

Ironically, certain Level 3 UPS's can also cause this kind of logic voltage drop. While these devices may advertise a fast transfer time in the event of a power outage, they are often unable to provide full power for one or two cycles after the transfer. In laboratory tests, computer logic voltage has been measured to drop as low as 3.5 volts when powered by some inexpensive Level 3 protections.

Solutions: Use a Level 9 UPS which have no transfer time when powering your computer to battery or use a quality level 5 UPS that will allow and compensate for sags with a buck-boost internal transformer. Need help with your selection? Contact Us.

When an I/O card, mother-board, power supply, or other vital component suddenly fails for no apparent reason, the failure is often blamed on manufacturing defect. In reality, the quality control and burn programs of most reputable manufacturers make built-in defects a rarity. The real cause is more likely to be latent chip damage caused by a high voltage spike, line noise or harmonic distortion.

You say you’ve protected you server with a surge protector, and you are still getting component failure? Surge protectors may protect against spikes, but does nothing for line noise and harmonic distortion. It is possible that the surge device itself has become the victim of repeated lightning strikes-especially if it is one of the cheap hardware-store variety. Or spikes could be seeking into your system via other routes, such as data cables or modem connectors.

Solutions: Be sure that all network devices are protected by high-quality, multi-stage surge suppressors, which carry a UL 1449 rating. Many level 3,5,and 9 protection carry this rating.        Contact Us to find the appropriate solution for your application. See to it that data cables and modern lines are also protected by  surge suppressors.

Symptom Five: Hard Drive Crashes

While this nightmare is less frequent than it used to be, hard drives still crash, and power problems can be to blame.

Sudden power loss can be especially dangerous to hard drives; if power fails during a read/write operation, the heads can drop precipitously onto the disc, damaging the delicate magnetic medium and creating bad sectors. If this damage occurs in the wrong place, disk boot failures may result.

Symptom Six: Corruption or Loss of Data in CMOS and Other EPROM Chips

Many computer users have experienced the horror of turning on their computer and finding that it’s suffering from amnesia; it no longer remembers how many drives it has, what kind of monitor it’s supporting, or how much memory is on its mother-board. Again, bad power may be the culprit.

Solutions: Protect Equipment with high-quality surge suppressors. Use various devices on the market (grounding wrist straps, touch-pads, anti-static sprays, etc.) to reduce the risk of ESD near your computer. Need help with your selection? Contact Us.

Symptom seven: System Devices Behave Erratically When Too Many are Turned On

If your network begins to behave strangely as more and more workstations are powered up, your problem could be harmonics, which show up on oscilloscopes as current or voltage distortions. Ironically, computers themselves are one of the biggest sources of harmonics, because their power supplies draw current in big, isolated gulps instead of nice smooth sine waves. If many of your network devices are powered from the same circuit, the harmonic content of that circuit can build as the devices are turned on. The result: the more workstations operating, the flakier they behave.

Symptom Eight: Frequently Aborted Modem Transfers

Power problems can cause modem uploads/downloads to abort or cause a high rate of block messages. The situation can arise when high-frequency spikes or impulses traveling on the power line couple into phone lines, which are almost never protected by any kind of shielding. These signals are then interpreted by the receiving modem as bad blocks.

Solution: Surge suppressors and many UPS systems are now available that include phone-line jacks. These devices can stop many of the impulses that travel on any phone-lines. You simply plug the modem line into one jack, and run another line from the second jack to the wall connection. Give one of these devices a try if aborted modem transfers are recurrent problem. Be certain the device you select is designed with a single grounding point for both the electrical and modem or data line connections. Need help with your selection? Contact Us.

Symptom Nine: Wavering Monitor Screens

If your display flickers, wavers, or dances, it could be a sign of larger power problems that may be affecting your entire network. Voltage sags can make monitor displays shrink. A wavering display could also be a sign of strong electromagnetic fields neat the monitor. Either of these situations can do more than just disrupt your screen; they can cause RAM errors, scramble data, and contribute to component failure.

Symptom Ten: Disk Drive Write Errors

Because your hard and floppy drives are really the only moving parts in your network, they are especially vulnerable to power aberrations. We’ve already looked at two reasons: damage caused by sudden loss, and RAM errors attributable to low logic voltage.

One additional way bad power affect disk drives is to interfere with the rotation speed of the disks themselves. Proper drive access depends on the correct rotation rate; undervoltages can cause the drive to try to read or write data in the wrong sector. Lost or garbled data, or actual drive failure, can result.

Is poor power quality causing all of your network woes? Probably not. Any device as complex as a computer is vulnerable to failure from many sources, and networking many deices together only compounds this vulnerability.

But don’t be too quick to discount the threat of bad power. A National Power Laboratory survey of 1,200 computer systems showed that the number of service calls dropped an average of 82% after the installation of a UPS.