Mac Plus- Ext HDD not spinning up + smoke

[Nagorak]

I recently dug my old Mac Plus out of the closet, and was hoping to copy the data off the hard drive in order to use it with a mac plus emulator on the PC (Vmac Mini).  The data is from when I was a kid, and isn't of any real importance, probably just some old school reports, some game saves and a few other silly little things I made.  I would like to try to recover it, but mostly out of curiosity. 

Unfortunately, things did not go as smoothly as I'd hoped, and I basically have a few different problems at this point:

1) The first issue is that the hard drive is not spinning up.  I opened the enclosure and discovered the hard drive was an ST251N and did some research.  Apparently this drive model commonly suffered from "stiction" issues, which would prevent it from spinning up.  Considering the drive hasn't been powered on in almost 20 years, I suspect that could very well be the problem.  I've tried powering the drive from a molex connector on my PC to remove the possibiltiy that the enclosure was at all, and the bottom gets very hot, but the drive still does not spin up.  Does this sound like "stiction" could be the issue, or more like something more serious, like the motor not working? 

2) The second issue is that external hard drive encloser is from CMS.  There are some dipswitches on the back that are presumably set up properly, but I really have no idea.  I have no manual or anything to go by, and it's hard to even tell what model number it is.  There are also two different connections for an SCSI cable on the back, neither of which are labeled, and I don't know which is the one I should connect to the Mac.  I tried connecting it basically at random (chose the top port), but that ended up with rather "interesting" results (see next issue; could be entirely unrelated to what port I selected). 

3) The third, and possibly most serious issue (depending on whether the HDD works or not), is that during the process of trying to get the hard drive running, I reached behind the Mac and pushed on the SCSI cable to make sure it was fully plugged in and making good contact.  The only thing I did was push on the end of the cable, but this must have somehow caused a short because there was a crackling noise and large amounts of smoke poured out of the top of the computer.  Amazingly the Plus still works (boots fine from a floppy), so the damage appears to have been isolated.  But I have to assume there's a good chance that the external hard drive port has been burned out. 

My main goal at this point is to try to get the data off of the drive.  If I can somehow gain access to the data (dump it to a file?) and get it onto my PC, I should be able to access it via Vmac Mini).  So, getting the hard drive working with the physical machine is only a secondary concern.  Ultimately, if the data is gone, it's not the end of the world, so I don't want to spend hundreds of dollars trying to get it back, but I am curious enough to spend a little bit to try to get the drive working again. 

The question is, what is the best way to proceed?  It seems like the first step would be to see if I can get the hard drive to spin up at all.  Should the ST251N spin up if connected only to a molex from my PC, or does it need to also have a cable connected?  What is the best way to try to get it working?  I've read that you can try to spin it clockwise, and also that you can try to smack it?  Are those really the best options or is there a better way? 

The second question is, if I manage to get the drive to spin up, what is the best way to access the data?  Can I just get an SCSI adapter for my PC and gain access that way in order to dump the drive contents, or do I need to get it working with a physical Mac?  I'd greatly appreciate any insight or suggestions you guys may have. 

 

[Nagorak]

Well, I tried smacking the drive and that did indeed allow it to spin up.  I then tried reconnecting it to the Mac Plus, and it starts to load but ultimately fails.  Considering I witnessed copious amounts of smoke coming out of the Mac Plus, I'm thinking the problem is probably on that end. 

Also it's clear that I connected the SCSI cable to the wrong port on the hard drive, so I don't know if that is what was responsible for burning things out, or whether it just happened because the computer is nearly 30 years old. 

 

[register]

Hello, please use the Seagate Installation Handbook. There is a trouble shooting section at the end of the document. Check for appropriate cables connecting related ports, SCSI IDs set differently for each device, proper termination, working power supply with correct voltage and polarity. The smoke may come from the electronics or just from burning dust. However, if the age of the electronics is a problem (as with leaking capacitors or batteries) prepare yourself for a prolonged tinkering session. Good luck!

 

[Nagorak]

I think I managed to get the hard drive set back up correctly.  It was put into storage in the same condition that it was when working, so it doesn't make sense the settings would have been changed.  It's unfortunate I didn't know about needing to smack the drive before I went to all the trouble to take the whole enclosure apart. 

I'm going to crack open the Mac's case tomorrow and assess the damage.  There was a whole lot of smoke and it didn't really smell like burning dust (strong "electrical" smell).  There was so much smoke that under normal circumstances I would expect the whole machine to be dead.  Maybe it could be from leaking capacitors, but I'm wondering if the SCSI control chip didn't get fried or partially fried.  Anyway, there's one way to find out. 

I'm hoping the worst case scenario is needing to replace the logic board. 

 

[techknight]

the smoke likely came from the analog board, probably blew open one of the output inductors or resistors. 

 

[CelGen]

That or the line filter caps blew. It sounds and looks really bad but it's harmless. Just remove them and you can continue working. It blowing up when you touched the cabling is pure chance and completely unrelated.

One thing if you have it is to floppy boot the machine and see if it mounts the disk. Not always promised the drive will mount because disk drivers in those days were weird but this can help get around a messed up system folder, which form your description you might have.

Also, I know the CMS enclosure you are talking about. I've had two of them. The dip switches on the back are a terrible design.

 

[techknight]

Yea, theres that. I forgot about the X1/X2 capacitors. 

Speaking of CMS drives, they must have sold a TON of those. I remember picking one up at the thrift store back in 1999 or so. 

 

[CelGen]

I would blame the line filters long before I blamed a more major component like an inductor or resistor. Second to that, you would be expecting cold solder joints. If all that checks out, THEN I would start suspecting the more critical components. You can't blow the SCSI controller unless you're exceptionally stupid.

If you really want to replace the filter capacitor, there are a number of modern capacitor types that you can replace them with, all of which do the job just as good. So long as the new parts match the old cap capacitance (your voltage rating can be anything between 240-600v) you're fine and they only cost $1-2 per capacitor.

 

[Nagorak]

It's good to know it's probably not the SCSI controller.  Honestly, that would be pretty poor product design if just plugging in a cable wrong could cause it to explode.  Also, if the chip was just flat out blown you wouldn't think it would read anything at all, whereas it does seem to get something, it just doesn't totally work. 

I still wonder if there's some sort of read issue though.  I can boot from floppy alright, but I tried booting from the hard drive three times and each time it got to a different point in the loading process before it freezes up or reboots.  If it were just due to corrupted data on the drive I wouldn't expect the results to be different each time I tried booting.  Then again, this is by far the oldest computer hard drive I've ever dealt with, so maybe it could be doing something weird. 

 

[CelGen]

When booting, try holding down the shift key to disable extensions and eliminate the possibility of a corrupt extension causing an issue.

Also, try leaving the drive spun up for a while before booting. The dynamics of those older disks tended to change as they warmed up because the platters were thicker and larger. I used to have a PC with an equivalent ST225N that would throw errors until you left the disk for half an hour.

 

[Nagorak]

Well, here's an update to what's going on. 

For some reason now when I turn on the Mac Plus with the external hard drive connected I get the sad mac symbol with the error 0F000A.  The Apple site says this error code has something to do with Line 1111, which unfortunately means nothing to me.  The error code appears before the flashing disc symbol, so it has to be before even trying to load the system. 

Sometimes I can still get the drive to show up on the Plus if I load from a floppy, and then restart the machine.  A lot of the time it gives me an error, saying the disk needs to be initialized, but if I've recently repaired the desktop file on the G3 (see below), I can intermittently get the hard drive to appear.  However, I can't copy anything to it as it just results in an error.

I also now have a PowerMac G3 and I can get the hard drive to appear on it, but every time it has to rebuild the desktop file.  When I scan the drive, with the disk repair utility, it reports there are problems that can't be fixed.  Also performance is very odd when connected to the G3.  It seems like the drive keeps stalling when it's accessed.  For example, the access light will blink and I'll hear the hard drive working (fortunately, these old drives are pretty loud), and there will be progress on whatever operation is running.  Then, after a few seconds, the operation will stall, while the access light stays solid on, and there is no audible hard drive activity.  Do these problems sound like what would happen if the drive was unterminated, or could it be due to the 3:1 interleaving that was used on the Mac Plus? 

I managed to get most of the data off of it, but larger files refuse to copy.  Due to the age of the drive, it's possible they're all partly corrupted, but it's weird in that it seems to apply to literally every large file.  Smaller files all copied off with no problems.  With the weird, intermittent disk access problems I'm wondering if there is some other access problem going on?

My next step is probably to re-open the external hard drive enclosure and verify whether the drive actually is terminated internally.  I was just a small child at the time, but I remember at one time we had two hard drives, so it's possible that when my dad removed the second, he didn't realize that the other one needed to be terminated.  Maybe it worked more or less fine with the Plus in the past due to how slow it was, but with the G3 it causes more problems? 

I'd appreciate any insight or advice you guys may have.

 

[Nagorak]

Oh, also I should add that I haven't yet had a chance to open up the Mac Plus to assess any internal situation.  The torx screwdriver I have access to turned out to be too fat to reach the deeply recessed screws, so I'm going to have to look into getting another one.