nCity Service Options

Replacement versus repair.: When a component part fails - be it a hard disk drive, optical drive. modem or whatever - standard procedure is to simply replace that component, which is usually your most cost-effective solution. First step is to diagnose the failure and (hopefully) its cause, second step is to locate and obtain an exact replacement, third step is installation, and the final step is to test and verify that the problem has been solved. Machine type will dictate time and difficulty required to extract and replace a component, towers being easiest while notebooks are usually most time consuming. Pretty straightforward, eh? Except that, as anyone familiar with computers will know, there are always complications.
: In any case, the majority of computer repairs proceed along those lines. Machines usually require cleaning, and there might be software and OS updates along the way, but - barring any surprises - once we've agreed on a course of action and arrived at an estimated cost, the job is as good as done. What surprises could there be, you ask? Scroll on down this page, then see "Damaged Goods" (link, left) for a few examples.....
: On the rare occasion when a component part can be repaired and restored to proper operation instead of replacement, that might well be the preferred tack to take; it may save both time and expense. You'll see examples of board-level repairs below, too.

Hard disk drives: It's only a matter of time...

The one single component most likely to fail and most often replaced, is the hard disk drive (HDD). Enormous storage capacity of modern drives, combined with rapid read/write operation and high-speed spindles, all combine to generate considerable friction and heat. Most HDDs have a one-year warranty, some have limited five-years warranties (replaced with factory-refurbished drives), but the maximum life expectancy of a modern drive is about seven years or less.

HDDs can fail suddenly, without warning, or gradually over time. A failing drive can produce errors and lose data, prevent a computer from starting up or cause it to freeze and/or crash. Mechanical failure is usually catastrophic, but the odds of recovering a fragmented, too-full or corrupted HDD are good.

Failed HDDs should _always_ be replaced with high-quality, new drives. Better yet, add a second matching drive for backup.

A few dead and dying hard drives.

Always: Backup, backup, backup!

Custom-made cable replacement.

Some replacement parts can be extremely difficult to obtain, especially when they have no part number or reference ID. Such was the case with a ribbon cable shown here (gray cable at top of photo, right), considered part of an otherwise functional assembly. The assembly in question happens to be front-panel controls which include machine's power-on button. Since power button's signal never reached the logic board, symptoms mimicked those of a failed power supply. To make matters worse, the problem was intermittent.

Having traced the fault to an open-circuit ribbon cable, we got lucky; we obtained a length of ribbon (blue) with proper connectors and had the correct crimping tool on hand for making a replacement cable.

Ribbon cable replacement.


Other internal replacement parts:: Power ports found in notebook computers (and certain other machines which use an external AC adapter) are a fairly common repair; these ports are usually located on a separate (replaceable) board. When a power port has been damaged, notebooks will still run from their batteries, but batteries will not be recharged.
: Internal boards and devices - PMU (SMU) boards, inverter boards, video boards, port boards, microprocessor boards, logic boards, and a slew of other subassemblies - power supplies, drives, cameras, microphones, etcetera - any one of these gizmos might fail, but each can be replaced at a reasonable cost.

Internal board replacements:

The most common of these are internal modems. Why? Because every time a thunderstorm passes thru the county, lightning strikes fry unprotected modems connected to phone lines. (I've yet to see any CPUs damaged by power spikes thru AC outlets.)

New or used replacement internal modem boards for most notebooks and desktop models are available from a variety of sources; these modems (like all internal boards) are machine specific, best matched by OEM part numbers. Some machines also have a second, separate EMI filter board that might also suffer damage from a power spike. (Later, Intel-powered Macs all use external USB modems.)

Other internal cards and boards which are separate from machine's logic board (like this ethernet card, right) allow for replacement if they fail; if this ethernet circuit were an integral part of machine's logic board, the entire logic board would have to be replaced to regain ethernet capability.

Internal 56K, v92 modems.

Ethernet card.

Internal optical drive upgrades:

It may be possible to upgrade an internal read-only (ROM) optical drive by replacing it with a read-write (RW) drive, either CD and/or DVD type on some machines (including notebooks) if RW drives were an option for your Mac. Towers will likely have an empty bay for a second drive, while iMacs and eMacs will not. Notebooks can be tricky because the miniature drive must physically fit, its connector must also fit, and the drive must be compatible.

The most important aspect of replacing internal optical drives is their ability to be used as a startup volume; if you cannot startup from a CD or DVD drive, troubleshooting a malfunctioning machine becomes a bit more complicated. Rather than replacing a working internal drive, adding an external USB or FireWire device is usually more cost effective.

Internal optical drives (CDs and DVDs).
Some replacements are easier than others.
DC-in port is where AC power adapter connects to computer, in this case a notebook (above). These ports get a lot of use, a lot of wear and tear, and can be damaged by rough handling. If port is mounted on its own DC-in board, replacing this board is usually a fairly straightforward process - when DC-in board is among the last parts installed during assembly. But that is not always the case. If you look carefully at the (left) photo above, what you see is an empty lower case with only the DC-in board and cable remaining; everything else must be removed in order to access this board, including logic board, frame, heatsink, display, drives and all. In addition, removal of heatsink assembly usually means replacing thermal pads and/or thermal paste (where heatsink contacts processors), adding still more time and trouble to this particular model's repair. (It could still be worse: The port could be soldered directly to logic board.) This job, on this specific model, takes about three times longer than most other Mac notebooks. (Newer laptops use Apple's "MagSafe" power connector - which should eliminate much of the wear and tear on power ports.)
Overworked power supply.

Size, wiring harness, heat and hazards put power supplies in a class by themselves. Some have safety features and filters, some have fuses, most have fans, and none of them should be tampered with or overloaded. Photo (right) shows an overworked SCR on a heatsink that baked its circuit board to a crisp before eventual failure. Power supplies have rated outputs that must not be exceeded, which is one reason why replacement units are always make and model or "family" specific.

AC-DC BBQ: Fried, failed, kaput.
Power supply specs and symptoms:: One advantage of tower machines over other desktop models is the machine's power supply. Towers are designed for expansion, with extra drive bays, memory slots and PCI card slots. All of these devices draw additional power, but a tower's built-in power supply is designed to handle the load; its wiring harness includes extra connectors to accommodate additional devices. iMacs and other desktop models have no provision for internal expansion, so their power supplies are more compact.
: Before assuming that a power supply has failed, be sure to check wall outlet, and any connected surge protectors, filters or UPS, power cables and connectors. Make no assumptions and double-check every connection. (We had one machine in the shop four times before its owner discovered a wall switch controlled the outlet she was using at home.) Once it has been verified that power is properly connected, check for other symptoms. Do any LEDs light up at all (even momentarily)? Is a fan running? Any signs of life at all? Some machines have safety switches designed to trip if they sense a fault, usually with an audible click, possibly protecting the power supply and other components as well.
: Replacement power supplies are expensive to replace and expensive to install. The power supply is usually the first component placed in a machine, and its wiring harness weaves its way throughout machine's cabinet; this means most - if not all - other components must be removed to gain access to the power supply. If bench testing indicates a failed power supply and it must be removed anyway, a replacement is usually expensive enough to justify spending a little more time on it to see if it can be repaired.

Logic board failure.

The logic board (sometimes referred to as a "mother board") is the heart and soul of any computer. Replacing a logic board is seldom necessary - with a few exceptions. One of these has to do with logic board connectors; specifically grid arrays, and especially those found in notebooks. Pin grid arrays (PGAs, top photo at right) allow "daughter boards" to be detached (unplugged) and replaced if necessary, but other array types do not.

Land grid arrays (LGAs) and ball grid arrays (BGAs, bottom photo) are soldered directly to the logic board, which means the logic board lives or dies with its attached daughter board. There are actually two BGA examples shown here; a chip soldered to logic board via BGA in top-left of photo, and a vacant BGA pad at lower right.

As you might imagine, BGAs can break contact if stressed or flexed, whereas PGAs - and to a lesser extent, LGAs - can absorb a good deal of stress without failing.

Pin grid array (microprocessor board).

Ball grid array examples.
Replacement-versus-repair of logic boards:: All component parts are available, new and used (as appropriate), including entire logic boards if necessary. In most cases, the quick and sure fix is to replace a failed component part - except possibly the logic board. Cost of a replacement logic board might exceed current market value of an older machine; replacement mother boards for new machines aren't cheap either, especially when you add the cost of disassembly, installation, reassembly and testing. In some circumstances, tho, a logic board repair can be a bargain.


System has detected a fault in USB bus, automatically disabling USB hub to avoid damage.: It's a judgment call determined by circumstances, and sometimes even a machine's warranty is best abandoned. The message above, for example, was produced by a brand-new notebook that had been dropped, landing on a USB plug which then hammered its USB port. The resulting short-circuit disabled machine's entire USB bus. Warranty does not cover accidental damage, and replacing an entire logic board due to a 25¢ port was just too costly. In this case, extracting the damaged port allowed second USB port - and computer - to function normally.
: On the other hand, five-year-old machines diagnosed with a logic board failure may be past the point of cost-effective repair, and your money may be better spent on a newer Mac. That said, read on for a few examples of board-level repairs that saved a deserving Mac or two from certain doom - and saved our clients hundreds of dollars in the process.....

Void that warranty!: This type of repair - disassembly, removing and replacing components soldered to a logic board and hoping it works - is the is the mother of all warranty-voiding operations. I'd never attempt this without making sure client understands that there are no guarantees, no promise of ultimate success, and a great deal of risk involved. But, if the only other solution is to replace an expensive logic board (not covered under warranty), then a repair might be worth a try.

USB port repairs:

A 10¢ resistor fails. A diode goes open-circuit. Repeated heating and cooling cycles cause a solder joint to crack. Cable strain and bulky adapters damage ports. Notebook machines get dropped, hinges break, displays fail..... These things happen, and such damage can lead to system malfunction and costly logic board or unit replacement. But, sometimes, a component-level repair can save hundreds of dollars, as illustrated here (right):

A USB port on this logic board was somehow destroyed - literally gutted - by its keyboard plug which came away with most of the port's plastic "tongue" firmly wedged inside. Metal contacts within the port itself were mashed against port's metal frame (ground), preventing the machine from even starting up. Not good.

Proper repair protocol would dictate replacement of the entire logic board, thereby replacing damaged USB port, but cost would equal or exceed market value of this machine. Instead, a component-level replacement saved the original logic board and put machine back in service.

G4 logic board prepped for new USB port.

Replacement port (white), installed.

Ethernet port repair:

This notebook Mac suffered a broken ethernet port when its cable was violently pulled from machine and the RJ-45 plug remained clipped to its port. In this case, the port came away more-or-less intact, but it took two printed circuit traces from the logic board with it. Machine was disassembled, PCB traces were carefully reconstructed, then port reattached, remounted and reinforced. This particular repair was a one-time-only fix; the port will not withstand any further damage. Client was urged to make use of the notebook's Airport card for a wireless connection instead of using an ethernet cable.

Ethernet port replacement.

SXKey repair:

LogicPro, an expensive high-end audio application, uses a hardware device called an SXKey for copy protection purposes. Without the presence of a licensed SXKey in computer's USB port, the program will not function.

When a client broke his SXKey one day, his studio came to a screeching halt. We managed to connect a USB cable and plug to the remains of his SXKey, then sealed the repair in plastic. Repair was successful and quick - if not very pretty - and client was back in business without missing a beat.

Broken LogicPro SXKey.
Nonstandard disc stuck in slot-load optical drive:: This is a relatively quick fix, involving a miniature, nonstandard CD inserted into a G5 iMac's optical drive. These small, oddly shaped CD disks were all the rage for a time; they work fine in tray-loading drives which have an indentation in the tray to accommodate such disks, but they're guaranteed to jam slot-loading optical drives.

This particular G5 iMac is easily opened for RAM upgrades and service; removing its back exposes all components - one of the nicer iMac cabinet designs. Three screws and a cable removes optical drive from CPU. A few more screws removes drive from its mount. Then comes the delicate part: opening the optical drive itself. With its lid removed (photo, right), the nonstandard CD can be seen wedged behind eject arm and drive mechanism in back corner of drive. Fortunately, no harm was done and drive functioned normally when reassembled. Drive replacement would have cost about three to four times as much as this repair. Incidentally, I had another slot-loader in the shop one day that had three CDs - count 'em, three CDs - all stuffed into its drive at once. I never figured out how or why..... but, miraculously, the drive still functioned after clearing it. An optical drive wedgie.
Salvaged notebook:

A trackpad connector broken from its solder traces on an laptop logic board. While this notebook worked perfectly with a mouse plugged into its USB port, its onboard trackpad was completely useless.

Unfortunately, to do the job correctly, this notebook had to be completely disassembled to remove its logic board from machine's frame for access to connector's near-side pins. Disassembly and reassembly of this particular model takes about three hours; add another hour or so for repairs.

Service cost was somewhere between a third and half the cost of a replacement logic board alone, without the cost of machine's disassembly, reassembly and testing. This repair was a real bargain, saving its owner hundreds of dollars.

How did the trackpad connector come detached? I have no idea. Luckily, the original connector was completely unharmed (aside from being detached) and finding a replacement connector wasn't necessary.

Using some serious magnification with a teeny-tiny, specialized, low-power soldering pencil, all eight traces were successfully reconnected and logic board repair completed. (Photo to right is enlarged almost 3x real size.) Continuity and cross-circuit tests passed, as did logic board testing.

Machine was carefully reassembled, entire system tested, and this notebook was back in service over the weekend.

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