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I have a hardware S-ATA disk imaging device here. You connect a SOURCE disk and a DESTINATION disk and the device makes an image of the source disk onto the destination disk.

After using for a couple of months, I started to notice something funny. Data on DESTINATION disk would end up being different (different size) from SOURCE disk.

So, I started do experiments with totally healthy disks and the same problem was re-occuring.

I contact the manufacturer and they immediately tell me "you need new cables, we'll send you some"

A week later the cables which use a S-ATA interface arrive. I dig out the disks which were having trouble. Sure enough, with the new cables for SOURCE and for DESTINATION disk connection, the disk image is the exact same as the source in size.

How did this happen? Can S-ATA cables wear-out?

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  • \$\begingroup\$ Are you talking about SATA cables? \$\endgroup\$
    – JYelton
    Commented Oct 18, 2023 at 16:30
  • \$\begingroup\$ Yes, S-ATA cables. But the one they supplies was the type where the power + data part are unified into one connector. \$\endgroup\$
    – daikin
    Commented Oct 18, 2023 at 16:34
  • \$\begingroup\$ Just to be sure, the Serial ATA has multiple layers of protection like CRC that data read or written was acknowledged to be received correctly. That is a problem if the device does not report any errors when connectors are worn out need replacing. Can it report errors? If not, you will never be sure if the source disk you just imaged was read correctly or the data was written correctly to target disk. \$\endgroup\$
    – Justme
    Commented Oct 18, 2023 at 16:54
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    \$\begingroup\$ @daikin I've never seen someone write it as S-ATA; it might be better to just call it SATA. \$\endgroup\$
    – Hearth
    Commented Oct 18, 2023 at 18:58

1 Answer 1

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Well, the cables (wires) themselves don't wear out. I am not aware of a wear out mechanism for copper. But the connector, or more accurately the contacts in the connectors can wear out after repeated insertions and removals, This is do to the fact that the very thin layer of gold that's plated onto contacts gets worn away (basically, rubbed off).

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  • \$\begingroup\$ ok, interesting. So what is the function of the gold - to assist in conductivity? \$\endgroup\$
    – daikin
    Commented Oct 18, 2023 at 16:35
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    \$\begingroup\$ Copper by itself forms a thin oxide on it's surface., which can interfere with conductivity (connections). One way around this is to design connectors with a wiping action when they mate, which breaks through the oxide, usually. Another way is with a gold coating. Gold does not oxidize. Better (costlier) connectors have thicker gold plating than cheap ones, and so can take more insertion/removal operations. In really critical applications, we use connector savers on the deliverable equipment. \$\endgroup\$
    – SteveSh
    Commented Oct 18, 2023 at 16:41
  • \$\begingroup\$ thanks! how do connector savers work and how would you define "critical" applications (examples)? \$\endgroup\$
    – daikin
    Commented Oct 18, 2023 at 16:51
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    \$\begingroup\$ A connector saver is just a male/female connector joined back to back. One end plugs into the deliverable equipment, and the other is used to connect up cables for testing, etc. This arrangement reduces the number of mates/demates on the deliverable equipment's connector, and also prevents the possibility of damage to a connector pin. Critical application in this example would be a satellite payload where a damaged connector could cost weeks or more schedule delay. \$\endgroup\$
    – SteveSh
    Commented Oct 18, 2023 at 17:52

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