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HINT: It may help you to print this page out, since proving the defect exists will require you to refer to several figures and pictures shown on this page. PROVING THE DEFECT EXISTS You are solely responsible for verifying this defect exists on your case and for any damage you do to your equipment. The purpose of this web site is only to make you aware of a problem that may or may not exist with your computer case. You should use the test procedure detailed on this web site to verify if the wiring defect exists on your Xaser III - DO NOT take my word for it. Just because I've never actually seen a Xaser III 1394 socket that was wired correctly doesn't mean they don't exist! If, however, you have some electronics knowledge and can easily work out how headers connect to printed circuit boards, this section of the web site will provide you with all the proof you need and show you exactly what to look for. I've received several E-mails from people accusing me of "making this up" to cover my butt for doing something stupid with my equipment, because the vast majority of people out there seem to think for some reason that it's impossible (or very unlikely, at least) for an OEM to ship such a massive defect to so many people. Well, you're certainly entitled to your opinion, and if you're one of those people, then all I can say to you is this: Get your own case, don't test it, and when you smell the magic smoke being released from your mainboard or peripheral when you plug it in, don't come whining to me! I have absolutely nothing to gain by creating this web site - I already received a check from Thermaltake to cover my damages. I created this site simply to give those people who were affected by this problem a means to verify their claims. I couldn't care less if you believe me or not; that's not the purpose of this web site. Now, on with the proof. The IEEE Standard document titled "1394-1995" describes in detail the standards used to construct 1394 devices. These standards apply to ALL 1394 devices, including the Thermaltake Xaser III. These standards and specifications detail the specific pins used to carry specific signals to and from attached 1394 devices. The first item addressed below is the official designation and location of 1394 signals found on a standard 6-pin 1394 socket as found on the Thermaltake Xaser III. This information can be found on page 56 of the 1394-1995 specification in Table 4.3 - Connector socket signal assignment and is shown below:
The above table shows which
signals should be present and where they should be located on the Xaser III 1394
socket. It clearly states that Contact 1, or Pin 1 of the socket, should
correspond to VP, Cable power, and that Contact 2, or Pin 2 of the socket,
should correspond to VG, Cable ground. On Page 63 of the 1394 specification, Figure 4.4 detailing the 1394 socket shell shows where the pins are located inside the socket:
IEEE 1394-1995 Figure 4.4 - Socket shell You can see from the above
figure that Pin 1 (VP) is located on the lower-left contact of the socket, and
that Pin 2 (VG) is located directly above Pin 1 on the upper left contact.
When comparing the above
information with the cable used to connect the mother board to the Xaser III's 1394 header, it is clear that the engineers
who
designed this cable did make some attempt to follow the IEEE 1394
specification, at least to some degree. Specifically, all of the wire colors
match the intended signal names, including VG and VP. This leads me to believe
that the 1394 wiring problem with the Xaser III is probably due to an OEM
manufacturing error where the VG and VP pins were swapped and then stuffed in
the wrong positions in the I/O header connector that attaches to the header
on the 1394 and USB connector printed circuit board. Each side of the I/O
Connection Header is
shown below:
A Known
Defective
Thermaltake Xaser III I/O
Connection Cable Header The next photograph shown below is a
close-up view of the Thermaltake Xaser III I/O Printed Circuit Board. This
board physically connects the mother board with the 1394 socket found in the top
of the case using the cable header shown above:
Using the socket IEEE 1394-1995 specification data shown above in Figure 4.4, I have labeled the 1394 socket pins on the bottom of the board shown below in yellow. Above that, I have labeled Thermaltake's pin header (shown above), using the wire colors and signal names exactly as they appear when the header is connected to this printed circuit board. The "KEY PIN LOCATION" seen inserted in the plastic header keeps the user from installing the header connector backwards onto the printed circuit board, and would be positioned in the area with no pins adjacent to the VG and VP signals.
Using the pictures and table shown above, you can clearly see that both VP and VG are swapped and do NOT match the IEEE 1394 Socket Specification shown below:
In reference to this problem affecting anyone who attaches a 4-pin 1394 device using a 6-pin to 4-pin 1394 interface cable, the IEEE 1394A-2000 specification page 40 - Figure 4-11J clearly shows how these devices can also be damaged by this wiring problem:
By following the wiring diagram shown above, pin 2 (VG) or "ground" on the 6-pin connector (left side of the diagram) connects via the shield wire within the cable to the outer metal frame of the 4-pin 1394 socket shown on the right-hand side of this diagram. That means that when you plug this style of 1394 cable into the Xaser III 1394 socket, you'll be sending POSTIVE 1394 bus voltage (not ground signal) via pin 2 of the Xaser III 1394 6-pin socket, through the cable shield, and to the metal frame of the 4-pin connector. In most electronic devices, this outer metal frame is connected to ground within the device itself. As a result of sending positive voltage to the device in this way, you create a massive grounding imbalance between the attached device and the 4 signal pins referenced from that "ground signal". The "ground signal" is now a POSITIVE voltage ranging somewhere between 8 to 40 volts, as defined by the IEEE 1394-1995 specification, page 26, section 3.2.1 titled "Cable environment." This section states that "The Serial Bus cable provides 8-40 VDC at up to 1.5 A. The actual current available is system dependent." This gross voltage imbalance will, in most cases, destroy the interface controller chip through which the imbalance is realized. This is what happened to my wife's Creative Nomad Jukebox III. Both the controller chip on the mainboard and the MP3 player were permanently damaged.
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As of 12/2005, this site is for reference purposes
only and is no longer maintained. |
