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Apple DUODISK

Ginu

New Member
Joined
Dec 2, 2021
Messages
8
Hi,
I have an Apple IIe to which I have connected an Apple Duodisk. The computer fails to boot. I have a fixed black screen with the word Apple ][ at the top and nothing more. The Duodisk drive A seems to rotate continuously and the red light is on, but nothing happens when inserting a floppy. What can it depend on?

Thanks
G
 
My recommendation would be to pull it apart and clean the drive heads as well as lubricate the sled rails. My Apple //c failed to read any disks until I cleaned the drive head.
 
My recommendation would be to pull it apart and clean the drive heads as well as lubricate the sled rails. My Apple //c failed to read any disks until I cleaned the drive head.

The cleaning of the heads and the lubrication of the sled rails has already been carried out. Could it be a head alignment problem?
 
Its supposed to be on spinning with a solid red light until it reads a valid disk. So open the drives and use some isoppropyl rubbing alcohol and q-tips to clean the head, make sure the felt pad is in place and clean the slide rails. DONT lubricate them. They are no suppsoed to be lubricated just super clean. Oil will attract dirt in the future. The drives also have a speed potentiometer on the bottom of each drive. A program like locksmith 6.0 can do a speed test and let you dial the speed in (between 280rpm and 300 is best. You need a working bootable drive to load the program though. The other issue could be the disk II card. They are pretty reliable but the proms on them fail from time to time. Start with the head and rail cleaning. Also what kind of disk are you trying to boot? If its an original it may have suffered disk rot and failed. You can use adtpro to connect the computer to a modern pc and transfer over new disk images to a formattted disk (you can format disks in ADT pro (you can alos boot adtpro without a disk using the audio/cassette ports on the back of the computer and your modern computers sound card.
 
Its supposed to be on spinning with a solid red light until it reads a valid disk. So open the drives and use some isoppropyl rubbing alcohol and q-tips to clean the head, make sure the felt pad is in place and clean the slide rails. DONT lubricate them. They are no suppsoed to be lubricated just super clean. Oil will attract dirt in the future. The drives also have a speed potentiometer on the bottom of each drive. A program like locksmith 6.0 can do a speed test and let you dial the speed in (between 280rpm and 300 is best. You need a working bootable drive to load the program though. The other issue could be the disk II card. They are pretty reliable but the proms on them fail from time to time. Start with the head and rail cleaning. Also what kind of disk are you trying to boot? If its an original it may have suffered disk rot and failed. You can use adtpro to connect the computer to a modern pc and transfer over new disk images to a formattted disk (you can format disks in ADT pro (you can alos boot adtpro without a disk using the audio/cassette ports on the back of the computer and your modern computers sound card.

Everything you've written I've already done, but it had no effect. The heads and rails are ok. The rotation speed is also ok. It seems to be a head alignment problem, but I can't find a right method to do it ..
 
The cleaning of the heads and the lubrication of the sled rails has already been carried out. Could it be a head alignment problem?

It's possible but, IMO, unlikely. While I don't have a lot of experience repairing disk drives I have observed head alignment issues tend to be rare compared to other things. Unless the drive has suffered a significant shock or someone has messed with it then I think it's unlikely. IMO the electronics would be more suspect than the alignment. You may want to inspect any capacitors for signs of bulging or leakage. Even a very slight bulge (on the top of the capacitor) can be a sign of a bad cap.

As already mentioned are you certain the disk you're using to test is OK?
 
It's possible but, IMO, unlikely. While I don't have a lot of experience repairing disk drives I have observed head alignment issues tend to be rare compared to other things. Unless the drive has suffered a significant shock or someone has messed with it then I think it's unlikely. IMO the electronics would be more suspect than the alignment. You may want to inspect any capacitors for signs of bulging or leakage. Even a very slight bulge (on the top of the capacitor) can be a sign of a bad cap.

As already mentioned are you certain the disk you're using to test is OK?

The only thing that makes me think it may be an electronics problem (as you tell me) is that the problem is the same for both drives. When you talk about viewing the electronic components are you referring to the analog card inside the Duodisk or to the controller?
 
OLDPCGUy is completely right about the alignment issue being highly unlikely. I fix Apple Floppy drives almost on a daily basis. Alignment issues are really rare.

You can try flipping the head cables on the analog board and using the right drive as drive 1 and test. You still havent mentioned what you have used for floppy media so Im going to assume its suspect.
 
Drive 2 behaves exactly like drive 1. I have another single Apple Disk drive ][ which works great with my floppy disks. The same floppy disks on the Duodisk are not read. If I try to format a blank floppy disk I get "track error $00"
 
The only thing that makes me think it may be an electronics problem (as you tell me) is that the problem is the same for both drives. When you talk about viewing the electronic components are you referring to the analog card inside the Duodisk or to the controller?
If the problem is the same for both drives that would lead me to look into the controller card first. One thing you may try doing is removing and reinstalling any socketed ICs that are on the board. Over time oxidation can interfere with the signal quality. The same applies to any socketed chips on the drives themselves. A visual inspection of both for bad caps may also reveal an issue. TBH the caps in these things seem to hold up well.

I assume you have neither another controller nor duo drive to test if one or the other is bad?
 
If the problem is the same for both drives that would lead me to look into the controller card first. One thing you may try doing is removing and reinstalling any socketed ICs that are on the board. Over time oxidation can interfere with the signal quality. The same applies to any socketed chips on the drives themselves. A visual inspection of both for bad caps may also reveal an issue. TBH the caps in these things seem to hold up well.

I assume you have neither another controller nor duo drive to test if one or the other is bad?

The components of both the controller and the analog card appear visually in good shape.
Unfortunately I don't have another controller and another Duodisk to try. I uploaded some photos to show the status of the components on the PCBs.
 

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The components of both the controller and the analog card appear visually in good shape.
Unfortunately I don't have another controller and another Duodisk to try. I uploaded some photos to show the status of the components on the PCBs.

It's difficult to tell anything from a picture, one really needs to have the physical board in order to do a thorough inspection. With that being said I have no reason to doubt your inspection, at least of the interface card (I'm not quite sure if you mentioned inspecting the drives themselves, is that what you mean by "analog card"?). One positive is all the chips on the interface card appear to be socketed, making testing them with replacements easy.

The only thing I can suggest, which I mentioned before, is to remove and re-install each chip that you can. I don't recall seeing that you mentioned having done that. If not the type of troubleshooting required to identify the problem is, IMO, outside the assistance I can offer on a forum.
 
Try swapping the D1 and D2 drive mechanisms, because chances are the D1 drive is a lot more worn out.
 
Try swapping the D1 and D2 drive mechanisms, because chances are the D1 drive is a lot more worn out.

As I said in a previous post, by swapping the drive mechanisms D1 and D2, D2 gives the same problems as D1.
 
It's difficult to tell anything from a picture, one really needs to have the physical board in order to do a thorough inspection. With that being said I have no reason to doubt your inspection, at least of the interface card (I'm not quite sure if you mentioned inspecting the drives themselves, is that what you mean by "analog card"?). One positive is all the chips on the interface card appear to be socketed, making testing them with replacements easy.

The only thing I can suggest, which I mentioned before, is to remove and re-install each chip that you can. I don't recall seeing that you mentioned having done that. If not the type of troubleshooting required to identify the problem is, IMO, outside the assistance I can offer on a forum.

In the photos I attached to the previous post you can see both the controller and the analog card that is inside the unit.
I tried removing all the chips and deoxidizing both the sockets and the chips with deoxidizer spray. After that I reassembled all the chips, but the problem persists ..
 
In the photos I attached to the previous post you can see both the controller and the analog card that is inside the unit.
I tried removing all the chips and deoxidizing both the sockets and the chips with deoxidizer spray. After that I reassembled all the chips, but the problem persists ..
At this time I do not have any other recommendations as it appears you've done all the general troubleshooting which can be done without getting into the actual component level testing. The only thing left is to examine the cable for any issues.
 
if you arent willing to go to those lenths you need another working disk controller card at least to start with.
 
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