The manual on that mobo is a bit confusing. It does tend to label all of its HDD headers as some type of IDE header, even though it actually has only ONE IDE header (could support up to 2 devices) and five SATA headers. A decade ago that sort of mis-labelling was common as SATA was first introduced. Despite the labels in BIOS Setup, any IDE port WILL allow for both a Master and a Slave device. On the other hand, any SATA port can have only ONE device. So on your mobo, any port called IDEn beyond IDE0 is actually a SATA port with ONLY one device, and NO Master or Slave designation. Thus, for example, IDE2 Master and IDE2 Slave really are two separate SATA ports.
But the thing I don't see above, OP, is that type of connection your DVD player really has. Is it SATA, or IDE? I would bet from your post that the SSD and HDD are SATA. IF your DVD unit is actually IDE and connected by a ribbon cable to the mobo IDE port, check the following.
1. Have you also connected a Molex power supply output plug to the DVD unit?
2. IF the DVD is a IDE deice on a ribbon cable, is it the ONLY device on that cable, or is there another sharing the ribbon cable? For now, I'm going to assume it is the ONLY device on that ribbon cable.
3. Read the label on the DVD unit regarding how to set its jumpers on the back edge. It will have a little map. Make sure to set them so this unt is a MASTER, or Master with No Slave Present.
4. On the ribbon cable, the BLUE connector on one end goes to the mobo IDE port. The BLACK connector on the other END goes to the Master device (your DVD drive) on the cable.
IF your DVD drive is really, SATA, then NONE of that applies. Still, it does need a power supply pluged into it. In that case, it is NOT a Slave, although it may be labelled as connected to an IDEn Slave position which is REALLY a SATA port.
If it is recognized correctly in BIOS Setup it MAY be working. But then, you need to have the device driver for that drive installed in Windows for the OS to be able to access and use it. You might also try running a drive head cleaner disk for CD and DVD drives through it in case its interior is dusty.