strange Cdrom/DVD roms problem

[redstar]

i replaced a cd-writer not to long ago (6 months). no problem
I added a harddrive to ide channel 1. At same time i may have switched my dvd rom(panasonic 16x) and cd rom around..(master becomes slave)

Not too long after (may be just a coincidence)..my dvd rom is failing to read more and more disks..but then so to is my new cd-rewriter.
At present, neither reads any disk i put in..and they don't stop trying to read until i eject the disk.

After putting in the disk into the cd-rewriter (the master on ide channel 2) ...the light keeps coming up on the other dvd rom drive (slave) (keeps trying to access it) until i reboot the machine.

Windows 2000 pro (sp4) insists the drives are fine ..and not all the cases of trying to read the cd generate cd-rom errors in the event viewer (even though i always have to eject the disk to get the machine to stop trying to read the disk)

OK. so i decide to disconnect the dvd rom to see if that is messing them both up.

Now here is the really...

STRANGE PART:

When i disconnect the slave dvd rom: The computer will not boot.
It beeps 2x fast (award bios code, i looked up, says this is a memory error --which it isn't) and displays the message ..INVALID(or incompatible not sure which) SLAVE DEVICE ..press F1 to resume.

At this point, i turn power off and reconnect the slave drive. The computer boots normally.

---

So..why will the computer not boot when i disconnect the slave?
I have double checked the jumpers..and they are set right.

I am left with the master..plugged into the end of the cable. I don't see why it won't reboot and then start normally.

Since i get the error message right away..before boot screen..perhaps DMI can't refresh and computer still thinks there should be a drive attached..??

Anyways, what do you people think is the problem ..or problems???

TIA

(just to be clear..i have 2 hard drives on IDE 1 channel)

and 1 dvd rom + 1 cd rewriter on ide 2 channel
--nothing is set to cable select (they are either slave or master).

 

[redstar]

followup. I bough a new LG dvd rewriter.

I put it all by itself on the ide channel as master.

got same error on boot (cept this time it went through a partial boot):

invalid slave device incompatible atapi. press f1 to resume.

So i threw in the old 16 x dvd rom --and it booted fine.
(for some reason my computer will only boot with 4 devices now)

But the new drive does work at least. So i guess that means my other 2 drives did fail at the same time.

so what's really bugging me now..is why i must have 4 devices or computer won't boot.

 

[Llamaman]

Not sure if this is the problem, but... have you checked that in BIOS your devices are set to auto detect? maybe it is expecting 4 devices and gets upset if there are less? i'd be surprised if this was it, but you never know!