Moody Hard Drive

[Olympiaman1010]

I just got a LCIII a few weeks back. I have my 100mb SCSI zip drive hooked and working perfectly. Since I got it, I thought it had a PRAM issue because I would have to turn it off and turn it back on several times. I got a new 3.5v 1/2AA for it and it seems the battery was not the issue. I next thought to zap the PRAM but to no avail.

Basically what happens is, in the mornings when I turn it on I have to listen and wait. When the hard drive spools down, turn it off and then back on, sometimes more than ten times. I hear both the system fan and the hard drive spool up. The hard drive makes two attempts to read the system files and disk shuts down leaving only the fan running. After several more tries I finally hear the tick, tick, tick I have been waiting for. To test it was the hard drive not the system, I put the system folder on a zip disk. When it doesn't want to boot from the hard drive and gives me the question mark I pushed the zip disk in. It booted perfect with only the sound of the system fan and the somewhat quiet loading of the zip disk.

Does anyone else have a moody hard drive that boots only when it wants to? I am fairly new to the 68K realm but have been working with computers since our family's first IBM 5150. I used Norton tools to check the disk as well and everything checks out OK. Once the computer is on and running the disk works perfectly and never gives me any trouble. It is truly amazing to be reunited with a machine that I spent hours on at friends houses. I also have a Mac 512k upgraded to a plus that is at my parents house that I would like to get going, I know it works perfect and is maxxed out. It even has the laser mouse! Now that I have a SCSI Zip drive it should make things easier. I never could do anything with the 800k floppys but with the external SCSI zip all those problems are solved. The only downside to the whole operation is having to use Tiger 10.4 to put everything on to zip disks because 10.6 decided to quit writing HFS files. At least I am still able to use zips and floppys as a read only so I can get the nostalgia of using the LCIII for word processing.

If anyone could help me with this hard drive hiccup that would be awesome. I would like to hear any feedback or thoughts on what I should do next. Or, if I should just deal with the trials and errors in the morning and forget the whole thing. Once the hard drive has been on for a while it restarts just fine and gives me no trouble, like I said, its only when it has been sitting off for the night. Thanks guys

-James

 

[Dog Cow]

Sounds like the motor that spins the platter is on its way to you-know-where.

 

[Olympiaman1010]

After 20 years I am sure most of the motors are this way, especially the ones used in schools. Should I look into buying another SCSI hard drive? Is there anything else it could be that I haven't thought of? Like the power supply or corrupt files bitmaps or data blocks?

 

[Olympiaman1010]

Does anyone else think it could be something else besides the disk motor?

 

[techknight]

nope. sounds like the drive is failing to me. pretty much it.

If you want to get a little bit crafty, you can stick an ammeter in between the drive molex and motherboard to measure the current draw. if the motor is going bad, itll be drawing locked rotor amperage for an excessively long period of time while the motor controller is trying to start it up. If i am not mistaken, i think they are 3-phase motors that are driven by a controller IC, kinda like a stepper. Or if its unable to draw hardly any current at all, could be power supply.

 

[Olympiaman1010]

Sounds good, I will get my ammeter out and report back. Which color wire am I looking to get the reading off of because I can't seem to get any reading off the yellow 12v. Any good places to get 50 pin SCSI drives besides the obvious, ebay? Also Sizes that I should look for... I heard I would only have a 2gb partition limit or something, can't quite remember but 2gb is more than enough especially because I have most everything on zip disks. Zip disks are so cheap now, but a good reliable hard drive is what I am now in search of.

Would it shorten the life of the drive motor to leave it on all the time so that I don't have to constantly put the motor through that strain when starting. LRA is 5 times higher than RLA and I can imagine it is putting a strain on the power supply.

 

[techknight]

If i am not mistaken, the 12V is the line that runs the motors, and the 5V runs the logic. its been awhile, i cant remember exactly, but this is the case for CD-ROM drives. so i dont see why it wouldnt be for hard drives.

If you have to, it may take a couple of ammeters on each supply line. But i dont think you need to go that drastic.

then look at the label of the drive, somewhere on there might be the total power consumption. Once you find this, youll know within what limits your looking at. for setting ammeter scales, etc..

Edit: If its not drawing anything at all on the 12v line, either the drive logic hasnt commanded the motor to startup, or the power supply is producing insufficient current.