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Internal SCSI Blues
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Feb 17, 2002, 12:38 PM
 
I'm trying to help a friend out who has been having hard drive problems. (I'm a bit of a tinkerer and I've opened up computers before.) I've narrowed the problem down to a SCSI issue. He has a UMAX PowerCenter 150. When I opened up the computer, I saw that the internal SCSI cable had physical damage. I replaced the cable. Whenever I have the hard drive hooked up, though, all a get is a blank grey screen. If I just have the internal CD-ROM hooked up, it works with no problem. But if I add the hard drive or if I just have the hard drive with nothing else hooked up, all I get is the blank grey screen. I imagine that this is some sort of termination problem or other SCSI issue, but I don't know where to go from here. (Note: it is a Seagate drive. I went to their web site and got the info about jumpers, etc., but at one point the drive was working, so I would imagine that I don't have to play around with these).

Any advice would be appreciated.
     
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Feb 17, 2002, 06:45 PM
 
Howdy,

Your instinct about it being a termination issue feels right. Your old internal cable might have had a terminator on it, and thus the drive didn't need to be set to term. Check the seagate site and find out how to term the drive. Also, if you can have the CD drive as your last item in the scsi chain, you might be able to sort this without any jumper changes.

let me know if this helps
ST
If its already broken, how can I mess it up by trying to fix it?
     
Kaps  (op)
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Feb 17, 2002, 07:09 PM
 
Thanks for replying.

I don't see anything that looks like a terminator on the original cable. (What would it look like?) The original set up was: Mother Board -> CD-ROM -> Hard Drive. The new cable has three connectors (besides the one to the mother board). I tried every possible combination and order of the hard drive, cd-rom, and empty connector. I also tried just the hard drive in each connector (without the cd-rom attached). All of these resulted in the blank grey screen. When I tried the cd-rom in any of the connectors by itself (without the hard drive connected), the cd-rom worked fine.

According to what I found from the Seagate site, the hard drive is terminated. I took the jumper off so that it wouldn't be terminated, but that didn't help either.

Any more suggestions?

Thanks.
     
Kaps  (op)
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Feb 18, 2002, 03:43 PM
 
Thanks for replying.

I spoke with my friend again to get a more detailed chronicle of the problem. Also, I researched several things and tried several things. Here is what I've come up with so far.

-Chronicle of the problem: At one point the computer, hard drive, CD-ROM, etc. were working fine. In Internet Explorer, when he tried to access a particular page, the computer always crashed. After one of the crashes, the computer wouldn't reboot. To see the hard drive, he had to mount it with FWB. He updated the disk driver, but he said that he might have updated the wrong partition by accident (he had two partitions). For a short period, he was able to boot up from the CD-ROM, but then he couldn't even do that (he would always get the gray blank screen).

-In comes me. I try to boot up from the CD-ROM and then try from an external Zip drive-all I get is the gray blank screen. I open up the computer. The set up is Mother Board -> CD-ROM -> Hard Drive. I notice that on the section between the CD-ROM and Hard Drive, there is a little section missing on one of the wires (on the gray ribbon). I assumed that that was the problem so I got a new SCSI cable. Someone on MacGurus told me, though, that that is how they come in Power Computing cables. Nevertheless, I do all my testing on both cables. The result of my testing was that whenever the hard drive was connected, whether by itself or with the CD-ROM, no matter where it was on the cable, I would get the gray blank screen. Without the hard drive connected, I could boot up with the CD-ROM (no matter where it was connected) or with the external Zip drive without any problem.

-I got information regarding the hard drive from the SeaGate web site. (It is a SeaGate Medalist, Model ST34520N.) I tried "playing" with the jumpers-turning termination on and off. That didn't do any thing. Then I noticed that there was an extra jumper on the bottom of the chassis. At first I thought it was for the hard drive (even though it didn't look like the picture that I saw in the SeaGate info). I tried that in every position. I then noticed that the extra jumper looked just like the jumper that was on the CD-ROM. It is a NEC CD-ROM and (bless their souls) they have a sticker on the drive that shows what jumpers do what. There are jumper on the first and second position (this sets the SCSI ID to 3). The third position was empty (adding a jumper there would set the SCSI ID to 7). The fourth position was empty (on the chart it says "Factory Use Only (Normal Off)"). The fifth position is "Termination On-Off." There was a jumper on that. And the sixth position was another "Factory Use Only (Normal Off)." There was no jumper on that. I tried the extra jumper in each of the available positions; I tried with the termination off-none of this helped. (Keep in mind that the CD-ROM worked fine without the extra jumper when the hard drive wasn't attached.)

I'm at a complete loss of what to try next.

Thanks.
     
Kaps  (op)
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Feb 19, 2002, 07:48 AM
 
SUCCESS!!! (But I still need some help.)

One of the first things I tried when my friend brought me the computer was to start up with cmd-opt-shft-del (to bypass the hard drive) and cmd-opt-shft-del-3 or just holding down the "c" key to try to start up with the CD-ROM. Neither of those worked. Throughout the trouble shooting, I tried that several times to no avail. Also, I tried resetting the CUDA. That didn't help either. I didn't remember how long I held down the CUDA button, so I figured that I would try it again (out of desperation). After I did that (this time pressing it for a good 30 seconds), for some reason, I thought that I would try cmd-opt-shft-del-3 again. To my surprise, the computer started to boot up. It froze in the middle of booting up, but it gave me hope—if only I could completely boot up bypassing the hard drive. Then I would run some utilities to try to resurrect the drive. Someone from the Apple Discussions suggested that I put the drive in an external enclosure, connect the drive (but don't turn it on), then after the computer booted up, turn the drive on and run any and all utilities that I had. The problem was, that I didn't have an external enclosure to try this. So, I decided to do a big no-no. I connected the drive internally, but just the SCSI connection, not the power connection. After the computer booted up, I then connected the power connection. I then ran Drive Setup and SCSI probe which recognized the hard drive, but for some reason couldn't mount them. I then ran Mt. Everything, and voilla, everything mounted (he had four partitions). Everything seemed intact with no loss of data. I then ran Disk Warrior. For three of the partitions it found some problems but repaired them and was able to create a new directory. For the partition that had the System folder, it found major problems and was not able to create a new directory. I installed a basic System on one of the other partitions and set that as the start-up disk. Now, everything seems to be working normally. The hard drive boots up from the partition that I installed it on and the other three partitions mount (even the damaged one).

Now where do I go from here? I know my first step is to back up everything! It will be a day or two, though, before I can borrow a Jaz drive. Should I re-initialize the whole hard drive or just the problematic partition? (Can I initialize only one partition? I've never had more than one, so I don't know how having several partitions work.) Is a regular initialization sufficient or should I do a low level format? He was using FWD before. Should I use that again, or just use Drive Setup? Is there anything else that I'm missing.

Thank you very much!

(Out of curiosity, how big of a no-no was what I did. Was it a "BIG NO-NO," just a "no-no," or, "given the circumstances, not such a bad no-no." Just because it worked, doesn't mean that it wasn't a no-no.)
     
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Feb 25, 2002, 09:58 PM
 
I do not believe any of this was a no-no, as long as you did not remove or reconnect the scsi cable while the computer was on. You may have to use another utility to set up the drive if drive setup doesn't recognize the drive. Good Luck
     
   
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