Let's start from scratch:
1. Remove new drive, leave the old drive there, make sure your old drive work OK, don't forget to read the drive ID detected when boot up.
2. Turn off, remove old drive and plug in that old drive to the second connector of the cable to test that data cable connector and Power distribution cable OK, turn on to make sure old drive works at the second connector / power cable.
3. Remove your old drive, plug in the new drive to the same known good cable connector and power cable you tested at step 2 above.
4. Turn on and read your new drive ID detected by your host adapter, make sure your new drive works alone first.
5. Turn off / set ID if you have ID conflict. Change ID on old drive if you don't have an option to change on new drive. Termination on to the drive end cable. Plug in both drives. Technically, they must work, unless you have incompatibilities controller. Yes, I see strange things daily between SCSI controllers / drives brand, models / PCs