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Timkorbs

PHP 1250 NOT READING OR WRITING

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So I had a TI994a and tape drive as a kid, but recently, for nostalgia's sake, decided to buy a TI994a with a PEB and try to use disks. When I started to use the system a week ago, it would read disks, but it was having trouble writing and I only got it to save a file once. Now, it will not read or write at all. The disk system is moving and making some sounds (but not the reading sound I heard before), I have tried cleaning all the contacts in the cards and I opened the drive and cleaned the head, but it looks totally pristine in the PHP1250 drive and the drive head was super clean. Any ideas of what I could try?? I also unplugged and re-plugged in all the connectors in the drive to no avail. The firehose cable looks really good also and I dont see any obvious reason why a wire would be bad in there, but who knows. Any thoughts? I am a newbie for sure. Error 56 and 66 are what I see a lot. Thanks for thoughts!

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5.25 disks are probably old, just like the 99/4A. Some HD floppies won't work as well as the DSDD types. Not sure what you're using, but another thing to look at while trying to chase it down. Were these disks already initialized with files on them? How many have you tried?

 

Always possible something got scrambled on the disk when a write went south. Can you reformat one to try it fresh? You need a disk manager cart or program on disk.

 

I had a problem with the LED that detects if the disk's write-protect notch is covered. Wasn't dirt, the LED itself went bad.

 

Another guess that also gave me trouble if I forgot about it, if the drives are uncovered and the room lights are bright, that can mess with the sensors too. Toss a cardboard cover over it or try with the lights down. If the drives are in enclosures, that's probably not it. Since you're testing, I figured it's possible you have it laying out exposed to room lights.

 

Could try very lightly lubing the rails the head moves on.

 

Usually when I have a drive problem, I just pull out another one from my TI hardware stash and carry on. I have a few I swapped out that need looked at now. Running low on spares... ;)

-Ed

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If the data is safe to lose, you could also try reactivating the iron oxide in the diskettes/break up the domain boundaries, by subjecting the diskettes to a degaussing wand/bulk eraser.

 

That would remove any bias the coating has developed from storing a pattern for a very long time, and make it more useful again after a good format.  Did that with a few of the 360k IBM PC diskettes I inherited. (they had attenuated so bad from sitting for 40 years, that the data was not recoverable-- so I reformatted them. Most were fine. Some that showed 0 signs of media damage insisted they had bad sectors after a format with aggressive test-- so I degaussed them a few times, then formatted them. Work just fine now.)

 

 

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The epoxy layer on drive heads can wear down over time from friction. I have a couple of DSDD TEAC drives, both of them scrape the oxide layer off of the disks, leaving clear, see-thru tracks on the disks. Needless to say this permanently damages the disks/data. I was told by the rather well-experienced giver that this would happen relatively soon, as they had seen much use. I've always imagined I would restore these myself, perhaps with some LOCTITE 242, 271, or 272 thread locker. I doubt I ever will though.

 

I dug-up a couple decent pics...

unnamed.jpg.f462dee5c008ade99dce899c206eb9fd.jpg

Epoxy layer removed... Scrape!:-o

Untitled.thumb.jpg.9ff4f68302cc4d025828e4b0e32d4524.jpg

 

This page has some useful info too...

 

http://www.retrotechnology.com/herbs_stuff/drive.html

 

Several repair videos are available on YouTube.

 

 

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Indeed! This problem ^ is why I specifically mentioned that I inspected the disk media to check for signs of such wear, and found 0 signs of it, in my case-- which is why I considered the issue to be likely caused by incorrect coercivity of the media, from large domains forming.  (and why blasting it with a randomizing, high power magnet with oscillating flux, could potentially fix it.)

 

You should ALWAYS be listening for sounds of scratching, scraping, and such when the media spins-- AND, you should regularly inspect the mylar surfaces of your disks to ensure that no scrape marks are on it.  Once the oxide layer starts getting scooped off like icecream, the particles can accumulate inside the dust sleeve of the disk, further damaging the media-- also, the abrasive particles sand-paper the epoxy coating on the disk head, further damaging the disk drive.

 

Always examine diskettes for physical signs of wear, then address accordingly.

 

Again, in my case, there were 0 signs of such wear, so I explored other potential sources of media reliability issues. 

 

------

 

Concerning the video and the bearings he has:

 

I would personally have submerged the bearings in isopropyl alcohol, and spun them while submerged, to help remove the old crud from the inside of the bearing assembly.  Often, once those seals fail, dust contamination is INEVITABLE.  The seizure is really from the dust gluing the bearings to the bearing race inside, and forming a thick tar-like goop.  Cleaning that crap out is necessary to properly restore the bearing.  It will move and sound SOOOOOOOOO much better after a thorough cleaning like that, than it will if you just relube it and move on. I find the same issue often is the culprit for failed ball-bearing fans.  You can often revitalize such fans and get several years of hard use out of them before they get noisy and awful again, after a good cleaning like that. (Eventually, the cumulative impacts of the dust infiltrations will cause pockmarks on the balls and the bearing race, as the particles promote irregular surface wear, and corrosion, which you cannot fix.) Once cleaned and dry, I would give them a slight shot of deoxit, allow to dry once more, THEN lubricate with a quality synthetic lubricant.

Edited by wierd_w
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Those Bearings have numbers stamped on them so easy to get replacements.

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Thank you for the help. I watched the video and have made some progress by rotating the stepper motor a bit and it has started reading my disks! For some reason I still cant save anything though??

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There is a notch on the top right corner of a floppy. If that's covered, the disk is write-protected. That, or the write-protect sensor in the drive is faulty.

 

Next, if that seems to be ok, is there room on the disk for your additional file(s)?

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6 hours ago, Ed in SoDak said:

There is a notch on the top right corner of a floppy. If that's covered, the disk is write-protected. That, or the write-protect sensor in the drive is faulty.

 

Next, if that seems to be ok, is there room on the disk for your additional file(s)?

Yep, I've definitely checked that. There is room also. Weird thing is I tried to save a small basic file on like 5 different good disks and it ruined the data on all of them because now I can't catalog any of them and they don't run the files that were on them! What the??? I have tried formatting disks and that wont work either...It starts to format for about 20-30 seconds and then says "Disk Error"????? However, like I said, I can read disks now, but read them only.

Edited by Timkorbs

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On 10/22/2020 at 3:39 AM, wierd_w said:

If the data is safe to lose, you could also try reactivating the iron oxide in the diskettes/break up the domain boundaries, by subjecting the diskettes to a degaussing wand/bulk eraser.

 

That would remove any bias the coating has developed from storing a pattern for a very long time, and make it more useful again after a good format.  Did that with a few of the 360k IBM PC diskettes I inherited. (they had attenuated so bad from sitting for 40 years, that the data was not recoverable-- so I reformatted them. Most were fine. Some that showed 0 signs of media damage insisted they had bad sectors after a format with aggressive test-- so I degaussed them a few times, then formatted them. Work just fine now.)

 

 

Gonna get a degaussing wand and try that, thanks!

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On 10/22/2020 at 7:48 AM, wierd_w said:

Indeed! This problem ^ is why I specifically mentioned that I inspected the disk media to check for signs of such wear, and found 0 signs of it, in my case-- which is why I considered the issue to be likely caused by incorrect coercivity of the media, from large domains forming.  (and why blasting it with a randomizing, high power magnet with oscillating flux, could potentially fix it.)

 

You should ALWAYS be listening for sounds of scratching, scraping, and such when the media spins-- AND, you should regularly inspect the mylar surfaces of your disks to ensure that no scrape marks are on it.  Once the oxide layer starts getting scooped off like icecream, the particles can accumulate inside the dust sleeve of the disk, further damaging the media-- also, the abrasive particles sand-paper the epoxy coating on the disk head, further damaging the disk drive.

 

Always examine diskettes for physical signs of wear, then address accordingly.

 

Again, in my case, there were 0 signs of such wear, so I explored other potential sources of media reliability issues. 

 

------

 

Concerning the video and the bearings he has:

 

I would personally have submerged the bearings in isopropyl alcohol, and spun them while submerged, to help remove the old crud from the inside of the bearing assembly.  Often, once those seals fail, dust contamination is INEVITABLE.  The seizure is really from the dust gluing the bearings to the bearing race inside, and forming a thick tar-like goop.  Cleaning that crap out is necessary to properly restore the bearing.  It will move and sound SOOOOOOOOO much better after a thorough cleaning like that, than it will if you just relube it and move on. I find the same issue often is the culprit for failed ball-bearing fans.  You can often revitalize such fans and get several years of hard use out of them before they get noisy and awful again, after a good cleaning like that. (Eventually, the cumulative impacts of the dust infiltrations will cause pockmarks on the balls and the bearing race, as the particles promote irregular surface wear, and corrosion, which you cannot fix.) Once cleaned and dry, I would give them a slight shot of deoxit, allow to dry once more, THEN lubricate with a quality synthetic lubricant.

Well, after messing around a lot, I'm thinking it's either that I have a failing floppy controller card or a power supply issue, or both I suppose. The PEB I have is in really good condition. Everything looks super clean including the internals of the floppy drive. I can tell this thing has not been used much. My most recent attempt at fixing this was to order a different floppy controller card as it seems as though the symptoms could relate to that being bad. It's still being shipped to me now, but I'll drop a note in here as to whether it fixes the problem or not. As a kid, I had a TI and a tape drive, but I'm new to the peb. I'm definitely learning as I go! Thanks for the thoughts.

Edited by Timkorbs

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So I got my new floppy controller and that solved the problem of the drive not reading. The drive was also continuously turning on and off and that stopped that issue as well. My issue now is that I cannot write to a disk. I can't format and I can't save anything to discs. has anybody ever had a problem where their floppy drive would read but not right?

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