Help with Apricot floppy drives.

[roadrash]

My lovely Apricot has stopped reading floppy disks. Not sure what happened but I tried a floppy from my apricot F1 in it to see if it would read it but then after that it would not boot any disks.
I guessed it must have been a dirty (oxidide shedding) floppy and removed the drive to clean the head (only one (single sided). Still no Luck. I originally got 2 of these Aprocot PC's and managed to get one working one out of the 2 machines. So I had a choice of 4 floppy drives I could use. They all worked but only one would read a disk and this is the one that has now failed as well.
Now I cant boot any floppies which is such a shame as its been working perfectly until I put the floppy disk in there to read it.
Then it got worse, I decided dismantle one of the spare drives to see what it was like. Well it was dead easy so and they come apart in complete assemblies so I wasn't altering things like the alighnment. I decided I might as we take all of them apart and give them a thorough clean out to see if I could get more of them working. Then once I put them all back togetherI tested them all.
They all still worked but again didnt boot a disk. Al that is except the one that had been working once before, that when went to test it started to make a burning smell. I killed the power and took it apart again to see what could have caused it. I never found anything was wrong with the way I put it back together but I noticed a very distorted track (from heat) and a 1S2348H diode was blown. I orderd some more and ive fitted a new one and all seems to be ok again but its still not booting any floppy.
Can someone please please help me get at least one of these old sony single sided drives reading and booting a operating system from a disk again. Here are some pics of the floppies.

 

[Stone]

A head cleaning disk is so much simpler, more effective and way safer than disassembling a drive. I just don't get it. It's akin to hunting an ant with a javelin. In 30 years I've never had or wanted to take a drive apart to clean the heads when 20 seconds with a head cleaning disk works every time.

 

[NeXT]

A head cleaning disk is so much simpler, more effective and way safer than disassembling a drive. I just don't get it. It's akin to hunting an ant with a javelin. In 30 years I've never had or wanted to take a drive apart to clean the heads when 20 seconds with a head cleaning disk works every time.

I beg to differ.
Typically by the time a drive needs its heads cleaned it's also a good time to preform a full cleaning, rail lubrication and inspection, especially in these earlier Sony drives where the top felt pad can get trashed by cleaning diskettes. I have really only seen drives get wrecked this way by people either dismantling the drives too far and knocking the alignment out or prying up on the top head and bending it out of alignment. The mac people are prolific offenders of this.

Verify that both the felt pad is in place and the solenoid operates when the drive tries to read/write. I am assuming that you do have known good Apricot formatted and bootable diskettes on hand? I seem to recall most Apricots from this era do not play well with traditional PC formats before DOS has booted.

 

[Stone]

I beg to differ.
Typically by the time a drive needs its heads cleaned it's also a good time to preform a full cleaning, rail lubrication and inspection,..

Time has nothing to do with it.

A new drive can need a head cleaning the first time you run a bad disk in it.

 

[roadrash]

There was actual lumps of grey fluff in the drives and that floppy I put in had left a oxide contamination on the heads. You cant get into these drives with taking off the top loading cradle. Its onlty 4 screws and it lifts off with chinging anything. The PCB is only 4 screws as well and then all the plugs are differnt so cant be got wrong. Its obvious they were designed modular like thgis for easy clening without altering critical things like head alignment. I had nothing to loose anyway now I have no working drives. These are sensitive drives anyway because only one out of 4 very good condition (except dusty) would read a disk. I have a repair manual for these drives but hoped someone on here might help me with checking all the right signals are getting to where they need to go.
I also have a Double sided version of these drives that comes from a Apricot F1 I have been restoring and is now woking except for its floppy drive as well. Its the disk from this computer I was trying to read when it did something to my only working drive. I now have 5 of these Sony drives to fix and if they are that tempremental then I need to find out how to sort thme when needed.

 

[jltursan]

I'm afraid I'm in the opposite side, I'm used to found these drives in all old Sony SMC machines (SMC-70 & SMC-777), the Sord M23P or HP external drive units and none of them have failed me...yet. The only problem I've found in nearly 100% of cases is the lack of lubbing, these units suffer a serious problem with the grease used, it turns into a thick paste that needs to be cleaned all over the mechanism. After the cleaning and applying new grease, all units came back to life.

So, no problem with drying caps or rotted magnetics heads, never found something like that in these drives. Maybe the Apricot itself gives them some bad life (electrically speaking) and they could suffer of PCB failures like your last one.

 

[roadrash]

I'm afraid I'm in the opposite side, I'm used to found these drives in all old Sony SMC machines (SMC-70 & SMC-777), the Sord M23P or HP external drive units and none of them have failed me...yet. The only problem I've found in nearly 100% of cases is the lack of lubbing, these units suffer a serious problem with the grease used, it turns into a thick paste that needs to be cleaned all over the mechanism. After the cleaning and applying new grease, all units came back to life.

So, no problem with drying caps or rotted magnetics heads, never found something like that in these drives. Maybe the Apricot itself gives them some bad life (electrically speaking) and they could suffer of PCB failures like your last one.

Thanks for the reply,

Lubing the head worm drive spindle was the first thing I did when I first restored the computer so I dont think that is an issue. There must be something in comon with all thee drives as out of 4 seemingly perfect looking and sounding drives I only ever got one to read a disk and it was dead reliable until I tried to read that floppy fronm the F1 Apricot in it. I'm a bit concerned about what you said about the heads because they are something I wouldn't be able to fix. I dont think its a Computer issue as when I turn on the Aprocot and it starts up it makes the drive do a sweep where the head is moved across the disk and back to track zero. Then a couple of seconds later it loads the heads to the disk again and spins up, this time I gather trying to read the boot track.
It coincides with a arrow on the screen pointing at a disk symbol indicating its trying to boot. Normally it would then boot into a slide show on the disk I usualy use. But now after it starts the disk boot it continues to read the disk and then after about 15 seconds it just stops. I can press reset agin and it will go through this process all over again but always fails at the boot track read.

 

[jltursan]

As I don't have Apricot machines I can't offer real knowledge; but it's obvious it's not a lubbing problem (this failure is very, very noticeable by a sticking insertion/eject mechanism), so, to be sure 100%, are you confident with the disks used?, are they in working state?. Over the years I've found that when using old disks YMMV and you can even temporarily ruin a head. As Stone suggested, after using a bad disk, a clean must be needed.

If you're sure the disks are good, it can be related to a bad head alignment (after a careless manual cleaning some double side units are prone to misalignments, this one being a single side unit is much harder to misalign), a head problem (no idea if these units develop this kind of disease, some Commodore ones suffered badly), a track 0 sensor problem (not usual in 3.5" units) or simply, a faulty PCB.

I still think that the problem is located in the PCB; but having no working units to swap parts with makes the troubleshooting a bit harder.