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Unable to boot disks.

Phipli

Well-known member
I am getting the question mark. If I power on the external HDD and turn on the Mac, then the screen is black for a short while and a second light comes on the HDD, until it finally ends up at the same ? disk screen.
The Plus here is very picky about booting from disks from other machines. I connected its disk to an 8100 which rebuilt the desktop while I wasn't looking and then it wouldn't boot from it any more.

I had to mount it on an SE and rebuild the desktop under an older OS (6.0.7 I think) to make it behave again.
 
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grone

Member
The Plus here is very picky about booting from disks from other machines. I connected its disk to an 8100 which rebuilt the desktop while I wasn't looking and then it wouldn't boot from it any more.

I had to mount it on an SE and rebuild the desktop under an oldee OS (6.0.7 I think) to make it behave again.
Unfortunately this is my only Macintosh, and only disk drive. I assume the easiest thing to do is buy one of the SCSI SD card readers so I can install a known working OS.
 

Phipli

Well-known member
Unfortunately this is my only Macintosh, and only disk drive. I assume the easiest thing to do is buy one of the SCSI SD card readers so I can install a known working OS.
If it's your only retro Mac I'd strongly recommend something that takes an SD card. Ask about for advice on which one, because be warned, SCSI isn't quite normal on a Plus and so some products will work better than others, or some will need more careful setup.

I suggested the FloppyEMU in part because while it still lets you use 2GB drives, it uses the internal or external floppy port instead of SCSI.
 

bibilit

Well-known member
Your Logic Board has been upgraded at some point.
The original one doesn't have that connector above the processor.

Also, have you replaced those RIFA capacitors (those next to the power connector) in the AB ? they can go the nasty way pretty quickly.
 

bibilit

Well-known member
Can you see or heard the drive spinning ? when the upper carrier is in bottom position, a switch is pressed down and the disk should spin freely.
 

Berenod

Well-known member
Also, have you replaced those RIFA capacitors (those next to the power connector) in the AB ? they can go the nasty way pretty quickly.
Concur!
When they go, they go ugly, leaving a horrible mess, like they emit, extremely stinky oily smoke, which sticks everywhere.
 

grone

Member
Can you see or heard the drive spinning ? when the upper carrier is in bottom position, a switch is pressed down and the disk should spin freely.
I can't hear the disk spinning at all. It's not jammed, because I can spin the drive when it's removed from the computer.

All three RIFA capacitors were replaced (with new RIFA capacitors).
 

bibilit

Well-known member
I can't hear the disk spinning at all

Not good... again troubleshooting with the drive hanging around should be easier.
protect the circuit board against any short and you are good to go.

On the front , you will see two tiny switches, one is for disk protection, the other one will spin the disk (have a try...)
 

grone

Member
Not good... again troubleshooting with the drive hanging around should be easier.
protect the circuit board against any short and you are good to go.

On the front , you will see two tiny switches, one is for disk protection, the other one will spin the disk (have a try...)
Ah! It does spin. I left the drive in place, and put a skewer through the front to depress the switch. It makes an abrupt digital sound like 'DE!' when it starts spinning, and again when it stops to eject the disk. I couldn't hear it previously when putting the disk in, because the drive drops at the same time as activating the motor so all you hear is the KACHUNK.
 

grone

Member
So, yeah, it's working now.

I remembered I had some 1.44MB disks in the garage. I didn't think there'd be any harm putting them in the Plus.

Chucked it in, and you can hear the drive trying to read the disk. It spits it out. So I put the Mac disk in, and still no luck. Tried the 1.44MB disk again, followed by the Mac disk, and now it boots!

Thanks guys.

EDIT: Rebooted and the disk isn't working again. But the Mac now sounds like it's at least trying to read the disk, and does initially give a happy face when you insert the disk. So it is an improvement.
 
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grone

Member
Tried to adjust the home position, but no matter what I did the disk wouldn't boot after the 'happy mac' screen. I was adjusting as best I could in 0.02mm increments using vernier calipers.

Adjusted the rotation of the worm drive motor. Still couldn't find a sweet spot to get the computer to boot.

I've ordered a floppy emu (road kill??) which hopefully works. The RAM is almost here.. so I'll try drive adjustments again once I've chucked the new RAM in.
 

grone

Member
Put the new RAM in today, but we're still unable to boot.

Coincidentally, the hard drive started working for the first time. It is horrifically loud - so I am assuming it has seized and only just became free enough to spin up.

When the HDD wasn't working, it would show a communication light, and the screen on the Mac would go black.

Now that it is working, the Mac screen doesn't go black, and I get a happy mac. But I've got the same problem as when trying to boot from a floppy, it won't get past the happy mac. It just cycles from happy mac, to X, back to happy mac.
 

Phipli

Well-known member
Put the new RAM in today, but we're still unable to boot.

Coincidentally, the hard drive started working for the first time. It is horrifically loud - so I am assuming it has seized and only just became free enough to spin up.

When the HDD wasn't working, it would show a communication light, and the screen on the Mac would go black.

Now that it is working, the Mac screen doesn't go black, and I get a happy mac. But I've got the same problem as when trying to boot from a floppy, it won't get past the happy mac. It just cycles from happy mac, to X, back to happy mac.
Does anyone live locally to you that could pop over with a confirmed working disk? Just to eliminate variables?

I live at "home" too, but have checked behind the sofa and didn't find you.
 

grone

Member
Does anyone live locally to you that could pop over with a confirmed working disk? Just to eliminate variables?

I live at "home" too, but have checked behind the sofa and didn't find you.

Fair point; I've updated my location.

I'll finally meet my neighbours. Come out come out, whoever you are.
 

Berenod

Well-known member
Coincidentally, the hard drive started working for the first time. It is horrifically loud
Not sure what you consider "horrifically" loud, but I assume it's a 20mb miniscribe in there, and they are loud. Very loud. Stupidly loud.
A floppy drive is whispering quit compared to a miniscribe 🤣🤣
 

Phipli

Well-known member
Not sure what you consider "horrifically" loud, but I assume it's a 20mb miniscribe in there, and they are loud. Very loud. Stupidly loud.
A floppy drive is whispering quit compared to a miniscribe 🤣🤣
Miniscribe has a stepper motor to control the head. Sadly I need to repair mine, one of a thousand projects :(.
 

grone

Member
Miniscribe has a stepper motor to control the head. Sadly I need to repair mine, one of a thousand projects :(.
Ah! Ta. I opened up the hard drive enclosure and added oil to the stepper motor - after a lot of power cycling it is mostly consistently passing the self test.

Although, it's still not booting.

Will have to wait until the floppy emu arrives before further troubleshooting.
 

grone

Member
I lied. Opened up the drive again because it once more stopped working.

Removed the stepper motor and *oops* the top two bolts were held in using washers and bolts INSIDE THE DRIVE! Eek. So I had to remove the cover and fish them out, then put them back in place.

The inner bearing of the stepper motor received a couple of drops of oil and it finally got rid of the crunchiness you could feel when turning by hand. Since I had the drive open, I put the smallest amount of oil on the shaft.

It's all back together now and passes the self test 100% of the time. Won't boot - but whatever, that's nothing new! Still gives me a happy mac.
 

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