|Software and Computer Systems Company, LLC|
In this article, we will be describing system problems that can exhibit symptoms similar to those associated with problematic hard disk drives (HDDs) and solid state drives (SSDs). In some cases the problems may be indirectly related to the drive, such as problems with a cable or I/O controller chip, and other cases they may have to do with the logic board, the supply, or even some of the system settings.
This page is one page in a series of five pages dealing with HDD and SSD problems and their associated symptoms. If you haven't read the main page of this article, we recommend clicking on the link to the left titled "Article Main Page" before proceeding. This article will focus primarily on problems specific to system components and it will not directly address any of the problems that genuinely originate from the drive.
For the sake of review and clarity, the symptoms we identified in the main page of this article were in the classification titled A problem with any of the system components and are as follows:
If problems cannot be attributed to bad or weak sectors on an
electromechanical hard drive (HDD) or bad blocks on a solid
state drive (SSD), then if the problems are system related they
may be associated with bad system cables, faulty I/O connectors,
improperly seated components, cracked traces in the circuitry of
the logic board, failing logic board components, or supply
problems. The most common cause of this problem is bad or poorly
seated cables. The symptoms of these problems are erratic delays
and/or I/O errors that are inconsistent, possibly inconsistent
booting, and applications locking up, to name a few. The
problems may become worse and improve as the system heats and
cools, respectively. These types of problems typically get worse
with time. Diagnosing these types of problems requires a
In all the other pages in this set of articles a specific resolution has been associated with a specific problem, but for this particular page the resolution will generally be similar if not identical from one symptom to the next. We would strongly recommend reading the sections on Drive Problems, Software Problems, and User Problems identified at the top of this page before assuming a logic board or related component is to blame.
If problems are detected during system tests, the first things that should be done are the following:
If any connections to a logic board exist that are erratic and intermittent, they may cause the system to go through a series of hardware interrupts each time the component intermittently disconnects and re-connects. This will cause system delays similar to a bad drive, but they will be erratic and non-repeatable. A good diagnostic tool will identify these as system faults. Some plug-in components such as improperly seated Airport cards or RAM chips can make a system look like it's completely dysfunctional when it simply needs to be re-seated.
Logic boards can fail either catastrophically or gradually. A catastrophic failure will be obvious because the system will usually crash during boot, or not even get to the point where it even starts to boot. A gradual failure can be related to intermittent connections on the logic board or anything connected to it, and components that are either failing or have an abnormal and irregular sensitivity to heat.
In the event an actual problem is detected during testing, the
options will be typically be one of the following:
Many logic boards, particularly those used on laptops, have the supply integrated into the logic board, and if there's a supply problem, then for all practical purposes it should be seen as a logic board problem. Most logic board problems cannot be serviced by a user. Some facilities offer logic board repairs, but very often the price of the repair comes close to or exceeds the cost of a new logic board.
External hard drives can have connector based problems because the connectors soldered into the logic board can be subjected to strain from lateral movement. Excessive movement of this nature can induce cracks in the base of the connector and cause erratic data transfers and possibly power interruptions. Some systems, such as older Mac Pro's and Power Mac's may have additional interface cards in the unit that may be susceptible to the same sort of problem, but in this case the problem will be with the interface card, not the logic board. External drives may also be susceptible to transient damage. Typically this will leave the port completely unable to recognize a drive or be used at all.
Periodic delays can be caused by problems with any component on
the logic board. When using a diagnostic tool, if the
problems can be traced to a specific path and they are
non-existent on other other I/O paths, then the problem is
typically isolated to that particular path. To properly evaluate
this will often require either an external boot drive or another
bootable drive in the system. When a path can be isolated to a
specific path between the logic board and a specific drive, it
usually implies the source of the problem is the cable
connecting the drive to the logic board. On laptops the
most likely cause is the cable connecting the internal hard
drive to the logic board. If the problem is with an external
drive, the problems may stem from cracked connections between
the board and the connector. This assumes that the cable has
been tested using a diagnostic tool or replaced and the same
If after performing the steps identified in the General
Resolution section above the problems still persist after
testing, the solution will be to replace the offending
component. If the path is isolated to the path between an
internal drive and the logic board the most likely failed
component is the cable connecting the drive to the logic board.
It is, however, possible that if the path between the logic
board's I/O controller and the connector to the drive has
problems, cable replacement will not fix the problem, which
would imply a logic board problem. The only way to confirm this
is by trying it with a replacement cable. If faults can be
detected on all I/O ports regardless of whether the drive is
internal or external, the failing component is likely associated
with the logic board, and the logic board will need repair or
replacement. If faults are detected during system bus tests the
logic board will need repair or replacement. If the supply is
found to be unstable, it will need to be repaired or replaced,
If the problem is with an external drive there's a good chance the connector between the board hosting the connection and the actual connector has developed cracks. If this is on a logic board the options will consist of replacing or repairing the logic board, or stop using the port. If the problem is on an I/O card found on some desktop units the I/O card may need to be replaced or the port not used.
For internal drives, failure to read or write data may will most likely be the cable connecting the drive to the logic board. If a cable has intermittent breaks in it, the symptoms will likely be very similar if not identical to those in the preceding section. If the data lines have complete breaks in them, then no data will transfer and it's likely the drive will not be recognized by the system. If there are intermittent breaks in the cables supplying power to the drive, the drive may exhibit both periodic ejections and read and write corrupt data between the drive and the system. If there is a complete break in the supply lines between the logic board and the drive, the drive will not be seen by the system and will not even power up. This assumes the logic board functions properly on all other system tests. Usually if a cable problem exists it will be limited to only one drive or path. If a stage of the of the I/O controller or an associated component has blown, which can often be transient induced, the drive will not be seen by the system.
Similar problems can exist with external drives, however it usually implies logic board damage to the connector or damage from a transient or, if the drive is port powered, the port may not be supplying adequate power to the unit. In the latter case, in many instances the drive may appear to power up when connected but fail to read and write data properly or consistently.
Verify that adequate power is being delivered to the drive and
replace cables if needed. Verify that all other functions of the
logic board are working properly. If bad or blown traces on the
supply lines on the logic board exist the logic board will need
repair or replacement. If an I/O stage component has blown the
logic board will need to be repaired or replaced. For port
powered external drives, ensure that the drive really is
receiving adequate power.
For internal drives, this is typically the cable connecting the
drive to the logic board or an erratic supply. Cable failures of
this type can cause bad data to be written to the drive. Power
supply fluctuations may cause data corruption while data is in
For external drives, excluding all the items covered in the section on external drive in the Drive Problems section of this set of document, it almost always points at a logic board problem or supply problem.
If the problem is a cable it needs to be replaced, otherwise
the logic board will need servicing or repair.
This is another side effect symptom of the problems described above in the subsection titled Periodic delays when using the system. Please refer to that section for more details.
If the drive is no longer recognized by the system, instead of being an intermittent failure there is a complete failure present.
On an internal drive, this can mean a complete break in one of the data lines or supply lines in the cable connecting the drive to the logic board, a broken or blown trace on the logic board, a broken solder joint on the logic board, or a failed stage in the I/O controller or an interface component. The problems will be the same for an external drive if the problem originates from the logic board.
If an internal drive cable is bad the cable will need
replacement. All other items will require logic board
replacement or repair.
In this case, the system can identify the drive (unlike the
preceding section directly above) but it won't boot from it. A
logic board problem of this type can occur if the symptoms are
intermittent, at which point it's essentially the same problem
as described in the section above titled Periodic delays
when using the system, otherwise the problem is more than
likely one of the problems identified in the sections of this
document titled Drive Problems or Software
Problems as linked at the top of the page.
Review the appropriate documentation described in the preceding
If an internal drive ejects itself for no apparent reason, it's likely a problem with the data or supply lines in the cable connecting the drive to the logic board. In this case we assume it's ejecting while in use and not a problem identified in the Drive Problems or Software Problems sections linked at the top of this page. This problem will be intermittent because if it wasn't the drive would never be seen by the system. Similar symptoms can exist if traces in data or supply lines on the logic board have cracks, blown traces, or bad solder connections. If an external drive is having this problem and it's been sourced strictly to the logic board then it will either be damage to traces or solder joints on the logic board, most likely those connecting the actual I/O port to the logic board.
If the problem is related to a cable, the cable will need to be
replaced, otherwise the logic board will need to be repaired or
In this case we assume that the drive spins up and is operational, then literally powers down. This differs from the preceding section where the drive intermittently drops out and comes back on line, hence appearing to eject. In this case it's likely a supply problem, or an intermittent short somewhere in the system. This will usually need to be observed on internal drives with the system opened up. Port powered external drives can show the same types of systems, but it would not happen on external drives that have their own supply.
The power supply and all connections, as well as logic board
traces supplying power throughout the logic board will need to
be evaluated to determine the source.
Scannerz, Scannerz Lite, FSE, FSE-Lite, Performance Probe 2, Phoenix, SpotOff, and Spot-O-Meter are Mac OS X universal binaries and support both 32 and 64 bit Intel based systems using Mac OS X versions 10.6 (Snow Leopard), 10.7 (Lion), 10.8 (Mountain Lion), 10.9 (Mavericks), 10.10 (Yosemite), 10.11 (El Capitan), and 10.12 (Sierra). Supported Intel based systems include all variants of the MacBook, MacBook Air, MacBook Pro, iMac, Mac Pro, and Mac Mini.