Hi, I’ve installed a second hand MSI KT4AV m/b after my old MSI KT4 got damaged
but when I boot up it does not recognize a primary or secondary drive. The HD
and CD drives are the same as before.? I can boot to the BIOS which says the primary and secondary IDE master and slaves are not installed although they are. Primary IDE master is set to auto.

When reinstalling a motherboard or any building/rebuilding part in a desktop, we tend to forget to check the settings of the small pins and parts of our old components.? Many times when we buy these components, such as optical drives or hard drives in your case, we never look at the pins and their factory set positions.

This problem is typically caused by incorrect jumper settings on the drives, or the drives are not attached to the proper cable connectors.? Lets examine what causes the problem and how to fix it to get the parts working back together again.

IDE cables typically come with 3 connectors, 1 for the motherboard, and 2 drive connectors. The first drive attached must always be the “master” and typically is attached to the connector on the opposite end of the motherboard connector. The “slave” connector is in the middle of the cable, but offset from the exact center, always closer to it’s master; this is how you can tell which belongs to what part when the cables are not labeled.

The jumper can be set 1 of 2 ways, (1) master (MA) or slave (SL), or (2) Cable Select (CS). You cannot mix the two methods on the same cable. This means if you use master, you must use slave for a second device on that cable, and you must ensure the master drive is connected to the master connector, and the slave to the slave. If using CS, all jumpers are set to CS. The master and slave is determined by the motherboard’s drive controller by the connector the drive is attached to. There can be no slave without a master, so a single drive on a cable will always be a master, and should be attached to the master connection.

Look at the back of the drive and note the jumper settings. Most drives have a illustration printed on the label. Ensure jumpers on both drives are set to CS, or one drive is set to MA and the other to SL. Then ensure the first drive, the master, is attached to the correct cable connection; again, typically the end opposite the motherboard connection.

Personally, I recommend using cable select because the only thing to consider is the drive’s position on the cable although MS and SL connections will work the same.

Here is an example of the back a drive for illustration purposes only – your drive most will most likely be a little different so check the label, manual, or maker’s website to be sure.

Finally, with SATA drives starting to dominate the market, newer motherboards are coming with only one IDE connector. But most computers in use today still have motherboards that support 2 IDE connectors. The first EIDE device attached to any motherboard must be attached to the first IDE connector, if more than one is present.

As a side note, I recommend the use of round cables of the appropriate length. Most round cables are labeled so there’s no mistaking which connector goes where. And round cables do not block desired front to back air flow like the traditional flat ribbon cables, allowing for better ventilation.

*Credit for this solution goes to: Digerati, a valued tech team member in our forums.