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SFD-1001 not formatting

D

Digitalman

Experienced Member
Joined
Sep 12, 2018
Messages
72
Ok, I have a weird issue with an SFD-1001 drive.

It will read from a disk, I can also save to the disk, but when I issue a FORMAT command the drive head moves, and the motor spins and then it just sits there. No error messages, nothing. You do not hear the head stepping as I would expect. After about 3-4 mins it stops and the disk in the drive is not formatted. Ive tried with 1S/4D 96tpi disks, and 2S/2D standard 360k floppies. The disk that I got that was preformatted is the same type.

I thought maybe leaky caps issues, so I replaced the drive PCB caps. Same thing. I cleaned the heads with alcohol and swab. One thing, I noticed, its hard to see but there is a thin rubbery looking ring around the top part of the head that seems loose. When I get the swab underneath it you can see it catch a little.

In any case, I am at a loss. Where would I go from here?

Thanks!!
 
Digitalman said:
Ok, I have a weird issue with an SFD-1001 drive.

It will read from a disk, I can also save to the disk, but when I issue a FORMAT command the drive head moves, and the motor spins and then it just sits there. No error messages, nothing. You do not hear the head stepping as I would expect. After about 3-4 mins it stops and the disk in the drive is not formatted. Ive tried with 1S/4D 96tpi disks, and 2S/2D standard 360k floppies. The disk that I got that was preformatted is the same type.

In any case, I am at a loss. Where would I go from here?

Thanks!!
Click to expand...
hmm no error messages? No flashing led? Does the head seek to track 1? What happens if you issue an I0 command with a formatted disk inserted? What command are you using to format the disk?

Frank IZ8DWF
 
iz8dwf said:
hmm no error messages? No flashing led? Does the head seek to track 1? What happens if you issue an I0 command with a formatted disk inserted? What command are you using to format the disk?

Frank IZ8DWF
Click to expand...

no error messages. No flashing lights. I assume it is seeking to track 1 as you can hear the head move initially. I'm using a C128 (in C64 mode), command below.

OPEN 15,8,15,"N0:TEST,A1":CLOSE15
 
Digitalman said:
no error messages. No flashing lights. I assume it is seeking to track 1 as you can hear the head move initially. I'm using a C128 (in C64 mode), command below.

OPEN 15,8,15,"N0:TEST,A1":CLOSE15
Click to expand...

It's really strange, I've never seen a CBM disk drive either finishing the format process or throwing out an error, but I've surely never seen a 1001 also :(
I'd suggest you to open the drive and make a video of the format attempt watching the head's movements, that would tell some more informations.
Based on my experience, when a floppy drive can read and write correctly on formatted floppies, it can still refuse to format disks because of bad or marginal media, but it definitely returns an error sooner or later.
It might be a bad track-1 sensor, but it definitely needs a closer look at what happens inside.

Frank
 
OK here is a quick video. Interestingly enough the timeout is a bit quicker. I'm sure i've sat there longer waiting got it to finish but this time (and subsequent) it was much quicker. In any case, it is the same result. Let me know if this tells anything.
 
I didn't expect the 1001 to have no track-1 sensor, but ok, it's probably typical money saving for CBM product.
Having said that, the behaviour is compatible with a bad media, but it's really very strange that it doesn't give any error, maybe the IEEE to IEC converter that you're using it's reading the error channel at the close15 and it clears the drive error. Ideally you should try with a proper IEEE computer and try a few different floppies.
The setup is enough unusual for me, so my help can't be much better than this.
Frank
 
iz8dwf said:
Having said that, the behaviour is compatible with a bad media, but it's really very strange that it doesn't give any error, maybe the IEEE to IEC converter that you're using it's reading the error channel at the close15 and it clears the drive error. Ideally you should try with a proper IEEE computer and try a few different floppies.
The setup is enough unusual for me, so my help can't be much better than this.
Frank
Click to expand...

Seems odd that the media is bad. I've tried all sorts of 4D and 2D. You may be right that the error is clear on the CLOSE15. If I issue the format without I see the same result although the LED on the case (the green one) turns RED at the end of the process. When I issue the CLOSE15 it turns back to green. Is there any tool or command I can use to pull the Drive status? I have a Zoomfloppy, maybe with CBMTOOLs?
 
Digitalman said:
Seems odd that the media is bad. I've tried all sorts of 4D and 2D. You may be right that the error is clear on the CLOSE15. If I issue the format without I see the same result although the LED on the case (the green one) turns RED at the end of the process. When I issue the CLOSE15 it turns back to green. Is there any tool or command I can use to pull the Drive status? I have a Zoomfloppy, maybe with CBMTOOLs?
Click to expand...

I would simply try this:
10 OPEN15,8,15,"N0:TEST,TT"
20 INPUT#15,E,E$,T,S
30 ?E,E$,T,S
40 CLOSE15
 
There is a sdf1001 diagnostic on my website in the commodore section, d80 format, in one of the d80 image directories. Load the program using an 8050 and then attach the sfd1001 power it on Run the program, it may tell you what is failing.
 
If he's using the SFD serially, it's doubtful that he has an 8050. Do you know how big the program is? I might be able to make a d64 of it.
 
I uploaded it here (D80 and .prg):
http://vintagecomputer.net/commodore/SFD-1001/

It could be the write protect sensor? Not sure if I remember all of how it works but generally-speaking it'll check the RPMs of the drive, the write sensor, ability to locate the correct track to initiate the format, stuff like that. I hate to tell anyone to blindly "replace the caps" but on an SFD-1001 that has never been touched, I'd replace the caps on the control board if I had no diagnostic equipment otherwise, see if that fixes the problem.

b
 
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KC9UDX said:
If he's using the SFD serially, it's doubtful that he has an 8050. Do you know how big the program is? I might be able to make a d64 of it.
Click to expand...

I am using an IEEE-488 interface card, but I most definitely do not have an 8050. billdeg, can you direct me to your website?
 
billdeg said:
I'd replace the caps on the control board if I had no diagnostic equipment otherwise, see if that fixes the problem.

b
Click to expand...

I believe I mentioned that already, but yes I did replace the CAPs. Although not all of the CAPs, I was going based on this procedure http://coffeemud.net:8080/ctcug/index.php/Recapping_C%3D_SFD-1001_disk_drives . I replaced all of the ones noted in the article.

Overall the board looks healthy.

FYI - My posts have to wait for a moderator.... which is frustrating.
 
Basically I think I should read this thread more carefully. Sorry using the mobile ap is clunky and now I am home at my main PC to be more thorough
b
 
Digitalman - please try to make a post without moderation. I bumped you up to 11 posts to give you member access. I assume it'll change your title when you make a post, but let me know.
 
Digitalman said:
Although not all of the CAPs, I was going based on this procedure http://coffeemud.net:8080/ctcug/index.php/Recapping_C%3D_SFD-1001_disk_drives . I replaced all of the ones noted in the article.

Overall the board looks healthy.
Click to expand...

Yeah! thanks! Ok, so again I replaced the CAPs using the procedure above. Is that sufficient or should I replace them all? Any of those CAPs specific to formatting or such? Maybe I can review my work and see if I mucked up anything. I assumed it was fine since the drive performed at least as good as it did before I replaced the CAPs.

Also, is the index hole sensor used by the SFD-1001?
 
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