Step 1:
Use pri IDE for your two HDDs. Set the HDD as Master and Slave accordingly. Don't use "CS". Connect your CD-ROM to secondary IDE. Try to turn on your PC.
reason: use the manufacturer's default settings, avoid testing uncertainty of "CS".
Step 2:
Change you pri IDE and second IDE cable.
reason: make sure the IDE cables are OK.
Step 3:
Use a good bootable HDD as pri master, your failed HDD as pri slave. Try both of your two failed HDDs.
reason: This step can test if you have any interactions between your two failed HDDs.
Step 4:
Good to HDD manufacuter's website or BBS, find if there is any failed report about your HDDs.
reason: it is possible there is some high failure rate for certain type of HDDs. As I know these days there are a lot of failed HDD found for IBM's HDD, esp. 30GB.
Step 5:
Give us your findings and let more people to think about it.
Use pri IDE for your two HDDs. Set the HDD as Master and Slave accordingly. Don't use "CS". Connect your CD-ROM to secondary IDE. Try to turn on your PC.
reason: use the manufacturer's default settings, avoid testing uncertainty of "CS".
Step 2:
Change you pri IDE and second IDE cable.
reason: make sure the IDE cables are OK.
Step 3:
Use a good bootable HDD as pri master, your failed HDD as pri slave. Try both of your two failed HDDs.
reason: This step can test if you have any interactions between your two failed HDDs.
Step 4:
Good to HDD manufacuter's website or BBS, find if there is any failed report about your HDDs.
reason: it is possible there is some high failure rate for certain type of HDDs. As I know these days there are a lot of failed HDD found for IBM's HDD, esp. 30GB.
Step 5:
Give us your findings and let more people to think about it.