XF551 Looks new but doesnt work.

[gobo]

Hi everyone

 

I was a long time Atari user. Was kind of obsessed. I got my Atari 400 in 1981 and loved it. While I've had an Atari emulator on every computer I've ever had (from Darek Mihocka's Xformer to Altirra), I recently got the urge for real hardware again. I bought my two original machines a 400, an 800XL, and a 1050. I went a step further and even bought the Atari 800 that I always dreamed of having back in the day! My 10 year old thinks they look "Powerful". I discovered I needed an XF551 because I wanted to look at some of the old programs I wrote again but they are save in the XF551 DS/DD format. I just got an one off of Ebay sold as "in box, untested, looks new". When it came I was pretty happy because the thing actually does look new, no marks at all and no dust, even in the creases. It even has that new smell to it! Unfortunately it doesn't work. When its turned on it makes a horrible head grinding noise and that's about it. I opened it up to see if there was anything obviously wrong but inside looks as new as the outside other than it missing that small metal shield that sits on top of the upper head. Is that enough to cause the drive to not work? I slid the head over and turned it on. The head moves back to the starting position then grinds. The metal shield is nowhere to be found. The SIO port solder joints look solid. I cleaned the heads with alcohol, even though they look immaculate. Does anyone have an ideas to what could make what looks like a new drive just not work?

Thanks for any help.

Tom

[spookt]

Silly question but have you checked the drive ID switches to make sure it's set to drive #1 (assuming it's the only drive connected)?

[Guest]

with the lid off can you tell if the drive head is (after it's initial powerup positioning) seeks or moves with a disk inserted?

the XF551 is very quiet when "in use".

 

any chance of doing a YT clip with lid off?

[Kyle22]

That sounds like a Track 0 Sensor to me.

[Bryan]

That sounds like a Track 0 Sensor to me.

Me too. If the drive mech is stepping then it's probably configured right.

[1050]

That sounds like a Track 0 Sensor to me.

Me three. Stepping out to track zero would be part of the power

up drive initialization still, it wouldn't be at a part of the

code to even query which drive it was yet. So selector switch

is not in play.

 

Missing head cover is not an issue, just an indication that

it got buzzed off there a long time ago by this same head

rattle if it can't be found inside the case. And they do

that quite often, it's only held on there with a fly spec size

drop of hot melt glue.

 

on1023.pdf

 

ON 1023 is likely to be the culprit and this device is only

the base unit, yours would have a soldered on flexible

ribbon connector which just might be the real issue and we

can't know that from here. You'll have to do some sleuthing

there and verify what's wrong with the zero track sensor.

You can observe the IR light emitted with the use of a cell

phone camera and then checking for voltages at the solder

points for the ON 1023 device might confirm where the problem

lies. That thin film connector can be 'released' by pulling

up a bracket handle on the plastic plug which is basically

just a wedge that forces the thin film contacts into intimacy

with the jack's rigid contacts. To often the new guy doesn't

understand that the handle for that plastic jack release

needs to be pressed back down in order for it to work again.

Or the card is not inserted correctly as in fully, etc.

 

Availability for the ON 1023 varies, I got ten when Aliexpress

was selling them, but they no longer do that IIRC. eBay

might have some but it's a slug fest trying to find exactly

that one.

 

And confirmation that this device is a drop in replacement

in the first place is still needed -- it very well may have

one or more components mounted backwards or bottom for top

as well. It's just a close match to the case so far. The

internals should work if their contact legs are in the right

places. Which is the unconfirmed part.

Edited February 20, 2017 by 1050

[Bryan]

Missing head cover is not an issue, just an indication that

it got buzzed off there a long time ago by this same head

rattle if it can't be found inside the case. And they do

that quite often, it's only held on there with a fly spec size

drop of hot melt glue.

 

My experience with the head covers is that they're mounted with small pieces of foam tape that disintegrate, like the stuff that holds those shields on the 400/800 lids.

[gobo]

Wow, thanks for all the help!

 

The dip switches are set to the Drive #1 position. When I turn the drive on the head just grinds in its position sitting towards the back side of the drive. The metal cover is nowhere to be found. Seems like its not really needed. It was held on with what looks like three tiny Velcro pieces which are still there. If I slide the head up manually then turn it on it slides back to its initial position then grinds. It looks like its probably the track 0 sensor you guys mentions. Never worked on a drive before but I'm going to attempt what Dragonstomper said to do. I also bought a drive on ebay just in case that I'm hoping is the drop in replacement Mitsumi D503V. The auction was actually for a D509V3 but on closer inspection of the photos the drive is actually the D503V. Hoping the sellers mistake is real. Got it for $16.

 

Thanks again everyone for the help. Will let you know if it works.

Tom

[gobo]

Well the replacement drive came but it didn't work, just not in the same way. It actually was the Mitsumi D503V that I was hoping it was and I thought it would be an easy swap. With the new drive in the motor to spin the disc spins up but that's it. Attached to the computer it just gives a "BOOT ERROR". When I opened it up to look inside I noticed that the head on the new drive doesn't move at all. So I figured, well at least I have a new track 0 sensor, so I installed that into the original mechanism but the head still grinds the same as before. I do notice now that with either track 0 sensor the head just sometimes slides to its default position without grinding, but still the drive doesn't work at all. It acts the same if its attached to the computer or not. Would it be a good idea to try to switch out the stepper motor from the first drive into the new one to maybe fix the head not moving? Could this all be the XF551's circuitry itself? Do the solder problems go beyond the SIO connectors? I'm at a loss.

[Kyle22]

Just slide the sensor a LITTLE towards the center of the disk. Try it. If it works, then keep moving it back until it doesn't work, and mark that position. Now, move it forward a little at a time until it works, and doesn't work again. Mark the position where it stops working. Move the sensor to the place exactly centered between the marks.

 

This is assuming a commercially produced disk is in, or one formatted on a known good drive.

 

Also, turn the drive off and on after moving the sensor each time

 

You should be able to get it close enough.

 

Absolutely DO NOT touch the stepper motor adjustment screws unless you have an alignment disk, an oscilloscope, and some diagnostic software. Edit: And you know how to correctly use the above mentioned items.

Edited February 24, 2017 by Kyle22

[_The Doctor__]

depending on what mode the xf is starting in at the time it is normal for it to tap the limiting bracket ever so lightly from time to time.....

the replacement mech may not have it's jumper setting on the drive set correctly....

I would not go about adjusting sensors etc. until I was sure the drive jumpered properly

Edited February 24, 2017 by _The Doctor__

[Marius]

That piece of metal on top is needed but the drive can work and should operate without too. The top shield plate is for what we would call the backside of the floppy.

 

Since the drive is new but thus part is missing and you hear noise that metal thing is probably still somewhere inside the mechanism on a place where it shouldn't be.

 

Perhaps it is fallen somewhere in the rotating part on the bottom of the drive.

[gobo]

Ok, Funny thing is even though I thought I looked thoroughly inside the drive and didn't see the top shield plate I actually found it! I saw that the disc was spinning slower the replacement mechanism I bought so I when I looked closer at the drive motor there it was wedged 90% inside it. After I got it out the drive motor works fine. I connected both the mechanisms to a PC but both just spun the drive motor, no head action at all. I think I replaced the track zero sensor from the ebay drive to the XF551 but it didn't make a difference. I say think because I am not sure which part actually is the track zero sensor. The attached pic shows which parts I scavenged off the other drive. The attached video shows what the drive head does when its turned on. Getting a bit discouraged. I guess its time to look for another mechanism.

XF551 Grind.mp4

[Marius]

The black thing on your pic closest to the powerconnector is the track zero sensor.

[Marius]

When I watch the movie:

 

That is probably indeed a failure in the Track Zero sensor or the connected circuit.

 

When the drive gets powered the drive head moves until it reaches track zero and then it stops. Since the circuit does seem to fail, the head tries to move backward when it hits the border which makes this awful noise. Don't do this too many times. That small flat cable goes into a connector. Make sure it is connected right. Watch where this finally leads to, perhaps you'll find something odd.

[1050]

One thing you need to keep in mind is that by default all PC drives

are jumpered to be drive 1 in a zero based count system. The

XF551 is expecting to talk to drive 0 and will not communicate

with drive 1 in a zero based drive count system.

 

Which means you will have to jumper any drive used in the XF551

to be drive zero which is the odd man out issue. Newer drives

can't even be jumpered to such a setting anymore.

 

Black circled device is the track zero sensor, if you want to

test the drive in the PC you will have to jumper it to be drive

1.

 

[_The Doctor__]

just another typical ebay crap-sandwich .... that sure does look like a track zero sensor issue..... a really crappy old cell phone camera or even household security camera can tell you if the infrared led is putting out..... just turn out the lights and look using the camera if you see a lightly illuminated slit or dot the led is good.... then it might be the sensor.... that can be tested by using an known good led and flooding the sensor with it.... I had and old television remote the worked for this pressing the volume up and holding it worked wonders but your mileage may vary... do both mechs exhibit the same behavior?

Edited February 27, 2017 by _The Doctor__

[gobo]

Thank you all again for the help. I tried the cel phone video trick to see if there was a led flash but I didn't see one. I also tried it on the other ebay mechanism and didn't see one either so it may be something I'm doing wrong. I also tried a TV remote to no effect. The drives don't behave the same when inside the XF551. They are the exact same model number. I think the ebay one has a dead stepper motor because when it's turned on it just spins the drive motor, no head movement other than an occasion minute slide. The XF551 original drive spins the motor head and moves the head. It looks like it wants to work.The grinding doesn't happen every time. Sometimes the head just moves to the default position quietly. This grinding happens if its connected to the computer or not so I guess that means its not an SIO problem. Strange that it happens only some of the time. It never seems to even try to read a disk though. The head always stays at default. Looking at the drive # select jumpers in Dragonstompers post, mine are different. There are 4 rows instead of 3 and drive 0 is the topmost row. You can see it in the picture in the post above. If I turn the drive on with the jumper in any other drive # position the head doesn't grind or move at all. Again funny because this thing, including power supply and manual looks new. Guess I'll try looking for another mechanism. My great deal is getting expensive!

[1050]

There will only be a LED flash with the TV remote pointed right

at the camera lens. AND you have to change a channel or 'work'

the remote too.

 

The XF551 track zero sensor will show a constant light although

it's in a shielded case and not much can get out. .5 millimeter

slit is all and you have to be in between the LED and photo

transistor. A small shiny bit of metal placed in the gap to

deflect the light is probably the only hope of seeing these

caged type sensors.

On the 1050 they are rude, crude, and naked, so easily seen.

 

I agree, very suspicious about that defect coming and going

with no reason it seems. And I'm 1050, not dragonstomper

just like you're gobo and not Space Invaders, don't worry

about it, plenty of new guys have made the same mistake.

Diagram is for another drive, sorry about that.

 

So you made me go find one and you have a problem.

 

 

This is mine and your thin film connector is half length and

coming in from the side too. The entire top of that white

jack lifts up to release the thin film connector. Somehow

someone botched that one real good. Where your diagonal cut

is in the thin film is in front of the right mounting

screw in my picture. You can just see the 'pad' on mine as

it enters the jack, this is a thicker section of doubled up

thin film but on the face away from us is tinned contacts

with three divots where the jack has pressed it's contacts

into the slightly wider sections on the double thick section.

 

So I see writing on this track zero sensor of mime.

 

Stanley KU121

 

Doesn't seem to bring up a single thing that's related to

this and a bunch of Stanley Kubric stuff just to make it

fun.

 

You could desolder the jack and use point to point wiring,

there is no need of the fast assembly gifted thin film nor

it's jack in the first place.

 

Since the thin film doesn't come with ON1023, it would have

to be point to point wired just as above too. We do what we

have to do. Keep us appraised of developments.

[_The Doctor__]

comes and goes wreaks of bad solder joints and the xf is notorious for this... you need to reflow the power, sio connectors, and anything that looks the slightest bit suspect... remember these are thin weak PCB traces. do clean careful work and don't be afraid of flux!

Edited March 1, 2017 by _The Doctor__

[gobo]

Finally gotten around to re-soldering the SIO ports. Also checked the other solder connections which looked good. No change. The ebay drive spins up when the Atari is turned on but no head movement and the original drive still grinds even though I switched out the Track Zero sensor from the ebay one into it. So it looks like two bad drive mechs I guess. Does anyone know of another common brand and/or model 360K drive that is compatible with the 551? I've been very luck so far with ebay. Kind of going overboard lately. Got a 400, an 800 an 800xl (with type 2 keyboard) and 1050 that all look and work like new. I always wanted both a 400 and 800 together for some reason! Guess I was pressing my luck and should have just bought the XF551 from Best Electronics.

[1050]

Just about ANY 360k drive for the PC will work in the XF551.

Set it to be drive 0 is about the only thing to be done.

 

FD.zip

 

Here is a non guaranteed list of floppy drives and their

aspects. Plenty of 360K drives to choose from in there.

This list was gathered a while ago and the site it came

from appears to no longer exist.

 

Teac FD-55BR is a fine looking substitute for the D503.

 

If you live in the States I would be interested in buying

your dead mechs. Send a PM for contact info if interested.

Waiting until you have a working XF551 is more than fine

too.

[enito]

Hi dont know if can help or something , but i have the same trouble, and inspecting the board, i discovered a missing part , looks like some smd resistor or something. Dont know if this necessary but i see some photos of mitsumi and have this missing part. If we can compare photo of this area and discover how i can fix, here the photo marked red the area missed part. Thx

 

https://postimg.org/image/ow3kcg5z9/

 

 

[Geister]

I hope it's not considered rude to piggyback on an existing thread. I also have a near new looking XF-551 (after much scrubbing, goo-gone, and IPA) and it also has a small problem.

 

When I bought it I thought it was fully working, but after playing around with it, I am starting to discover some problems The first thing I noticed was that the power connector was a bit touchy. Reading through the posts on here I learned about the problems with the fragile circuit board, so I pulled the unit apart and examined the solder joints and found that one of the pins on the power connector was cracked. After checking for other problems and possible upgrade ROMs (there's a funky 3-way toggle switch on the front panel) I can report that there are no other cracked joints, nor are there any upgrade roms. The toggle switch may have been an attempt at a quick drive select mod but I think it failed and the previous owner just left it in place rather than have a hole in the bezel. In any case, as long as the switch is in the center position, the drive will read and boot a DOS disk.

 

So what's the problem? The drive can't format a disk in DOS 2.0 format (It's the only DOS I've got at the moment). I thought it might just be bad floppies (I was trying to format them because they couldn't be read.)

 

I read somewhere that these drives can lose the 12 volt supply and that can cause it to be unable to write or format disks, and yet, still read them. While I had the drive open, I checked that both the 5 volt and 12 volt supplies were working...the 5 volt supply was providing 4.95 volts and the 12 volt supply was around 11.8 volts. Unless the 12 volt requirements are really finicky, that should be enough power, but the drive still will not format. When asked to format a disk, I can hear the stepper motor moving and I count 40 steps before It makes a slightly different sound (Writing the boot record?), then there's a pause and the stepping repeats. This happens for a few repeats until the controller gives up and the drive reports error 173 (Can't Initialize disk).

 

Now, I can be a bit slow, so it only occurred to me to check whether the drive could even write to the disk hours later. I set everything back up, and wrote a small basic program and attempted to save it to disk. It worked perfectly. I was able to read the file back in and execute it, so the write was successful, and legible. I wrote to the same disk that I couldn't format earlier, after formatting it with a 1050 using DOS 2.0.

 

It could still be a bad floppy that the 1050 was somehow able to hammer through. I did think it sounded like the 1050 was kicking a bit over a weak sector while formatting, so maybe the XF-551 will be OK if I ever get some new old stock disks. I just recently bought the computers and drives from a surplus warehouse (not new surplus) and bought some used disks that had Atari titles on them. Perhaps they've just been setting too long and only the 1050 can plow a new set of ruts through them.

 

I've never owned an XF-551 before, so I don't know what to expect of them. Anybody seen this before?

 

I did have an 810 and a 1050 with a US Doubler in the past, and the 1050 was a beast using SpartaDOS 3.2. I'm hoping I can find a way to get the doubler in this new 1050.

Edited January 15, 2018 by Geister

[Mathy]

Hello Geister

 

I hope it's not considered rude to piggyback on an existing thread.

 

It's better to open a new thread. You want people to respond to YOUR problem, not the one topic starter has/had. And it wil be easier to find back your problem when needed.

 

Sincerely

 

Mathy