Basic Hardware Problem Diagnostics

We'll walk you through the steps for diagnosing and fixing some basic hardware problems as well as show you how to get the most out of your service and technical

October 22, 2004

6 Min Read
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If your hardware is under a warranty or service contract, contact the manufacturer or representative to repair it. Opening the box or messing around with the internals of the workstation to find a problem could void your coverage.

DIY: Proceed With Caution

If the equipment is no longer under warranty or service contract, you can take a shot at diagnosing and fixing it yourself. But don't service any equipment with a CRT unless you know what you're doing. CRTs can carry a major charge even when unplugged, and you can be seriously hurt if you don't take the proper safety measures.

For other pieces of equipment, make sure it is unplugged, and that you're using antistatic protection--a grounded wrist strap or heel strap, for instance.

Next, look carefully inside the box. Do you see signs of damage? Are there any scorch marks, cracked or melted components, or frayed wires? Don't be fooled if the damage seems minor. Even a tiny crack on the outer casing of an IC can indicate failure of the silicon inside. Scorch marks on the main circuit assemblies or wires leading to them can also spell trouble.Examine the aluminum electrolytic capacitors, the small components that look like miniature beer cans. (They have two legs coming out of the bottom, though the legs may not be visible.) Their exposed tops have two lines crossing at the midpoint, so if a capacitor overheats or shorts, its top will burst or bulge. Some capacitors have a slight dome, but if there's a significant bulge or split in the top, it's likely that the capacitor or another component down the line has failed.

Another diagnostic step is to use a voltage meter, preferably an autoranging one. But don't try this if you're not familiar with voltage hazards and electronic equipment. Plug in and turn on the equipment in question. Find where the DC power leads traverse from the power supply to the circuit board. Carefully touch the tip of the black negative lead to a ground point in the equipment--usually a metal frame or the metal outer covering of the power supply, if there is one. Insert the positive lead at the top of the wire connecting the power supply to the circuit board. You should touch the top half of the crimp in the connector wire.

Why not just pull off the connector and read directly from the power supply? Because many power supplies require an electrical resistance load, provided by the circuit board, to power up. This is especially true in PC and server power supplies: Without a load, they won't function. And measuring the output of a power supply without its load is almost worthless because the voltage will vary considerably and the readings you get won't resemble those taken under a resistance load.

Now read your voltage. In most cases, a black wire should have little or no reading. Other typical voltages for any nonblack wire range from 48 down to 1.1 or 3.3 volts (you typically get 5 volts, 12 volts or 3.3 volts, either negative or positive). As a rule, the higher the voltage, the more acceptable the variance. If you're measuring a device that's supposed to be 12 volts and it's 11.5 or 12.7, no big deal. A voltage variance that large on a 3.3-volt lead, however, would be a red flag.

Take a sniff of your hardware. Is there a burning, sick-sweet or acrid smell? A burning or acrid odor comes from plastics or insulation, and a sweet smell is usually burned resin flux, which is used to clean electronic components and let solder flow. Most circuit boards have a small amount of flux, and you can sometimes smell when it heats up or burns. Any unusual smells may indicate a failed component.These diagnostics let you determine the extent of the damage so you can gauge what it will cost you to repair or replace your equipment. Most organizations simply don't have the time or resources to do component-level repairs. In many cases, it's cheaper to replace equipment than to repair it, especially if the hardware is old.

Rolling Up Your Sleeves

Sometimes hardware doesn't fail completely. A specific function, like the loading mechanism on a tape drive or the fan on a PC, for example, won't work. It's difficult in these situations to discern whether the problem is with the configuration, the software or the hardware itself. Again, take a diagnostic approach. Reset the configuration to factory defaults and set it up from scratch.

If it's a PC or PC-based server that gets a software load, reload from scratch if possible, or load a backup of the software onto an identical machine to help you determine the problem. A software problem, for example, will manifest itself on the other machine as well. Make sure that cables are plugged firmly in and firmware (BIOS) settings are as they should be.

Memory-test software is a good first step, but not the definitive one. We've had machines in our Network Computing Real-World Labs® that run these supposedly comprehensive memory tests for days, and the machine still ends up needing a memory replacement. If you suspect memory failure after eliminating configuration and software problems from your list of suspects, reseat the memory and replace it wholesale. If you're still having problems, it's time to call in the professional service technicians or ditch the hardware.Meantime, carefully sleuthing a hardware problem is an effective way to avoid costly repair, especially when software and configuration issues are the cause. But don't get burned: Take the necessary safety precautions, and know when it's time to enlist outside help.

Steven J. Schuchart Jr., a former Network Computing technology editor, is an analyst for competitive intelligence firm Current Analysis. Write to him at [email protected].

Think you know your service contract? Think again. Most companies assume that signing one gives them instant service by competent and friendly people who happen to be located next door.

It's time to get real. First, understand the warranty or service contract. Know response times, parts shipment times, hours of service and technical support, and whether the package includes software/firmware/OS upgrades. This prevents manufacturers and resellers from denying you service and keeps your expectations in line with reality. Establish a relationship with not only the service person, but also the dispatcher you call.

When calling or messaging a tech-support line or service-dispatch center, maintain a polite but firm tone. Make sure you know your serial numbers and model numbers before you get on the phone. Don't raise your voice, yell or swear at anyone. That can come back to haunt you and your company when the going gets tough and you need help ASAP.If you're not getting the proper support, you may need to speak with a supervisor to ensure that your warranty and contractual obligations are fulfilled. (The supervisor is more likely to be responsive if you haven't verbally abused the dispatcher or repair technician.)

Consider inspecting the quality of repairs to your equipment under the contract. That doesn't mean watching over the technician's shoulder during the repair. Rather, have the person show you the repairs before he or she closes up the hardware. Ensuring that a repair is worth what you're paying saves time and money in the long run.

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