Hi!
I've replaced the drive belt on my 6128 and the disk spins up OK, but it looks like the read/write head doesn't move. It just makes a buzzing noise when you do e.g. a "cat" with a disk in the drive:
http://www.youtube.com/watch?v=DX1DN0Jaz0Q
So, is the motor broken? But then why does it hum like that?
I can move the read/write head by hand by turning the metal rod on the right, so there doesn't seem to be anything in the way.
Martin
Sometimes the head get blocked by the "endless screw"..
So just "turn" this endless screw so the Head is no more blocked on max.
Of course this can not be that, but I had such case...(and actually had to re-open my amstrad, removeing again a lot of screw...)
OMG the head move no more ? well the endless screw ("vis sans fin" in french) has gone on max in one of direction so it is blocked... er... Jamed...'(bump up the jam!)
Just get it a bit back with your hands (fingers, dick, whatever)... by turning on its axis the endless-screw (which actually has an end...lol...)
May work in a lot of case.
Testing a disk drive with no Belt can drive to this, as the head reach the end of its screw reach because the disk can't turn... so it search a lot... (sort of)
and when a screw is turned to the max, it jams itself...
Hope this is it, as screw concept is hard for me to explain in english... we all know love language (screwing tongue) is french... lol... ;D
Hope this is only it.
Needless to say, you must "open" your Amstrad so your finger (or dick or whatever) can access to this "endless screw"... :P
Principle of the endless screw :
(http://kmoddl.library.cornell.edu/stillImages/Chicago/small/005.jpg)
just replace the clockwork wheel with the head of the driver... ::)
As the reading/writing head is translation based instead of rotating...well the endless screw actually has an end then...lol...
Ouch, my sexual life is so pathetic... :laugh:
Thanks, MacDeath!
However, I can turn the "endless screw" (by which I assume you mean that thingy sticking out of the stepper motor) all the way by hand. Are you sure this can be the problem then, if I can move the r/w head all the way forward and back manually?
But I'll look into this possibility.
Martin
Mal eben auf Deutsch:
Sieht so aus, als ob der Greifer, der auf der Schnecke sitzt, defekt ist.
Dort ist normalerweise ein kleiner Metallstift drin, welcher in die Windung rastet.
Schau mal nach, ob der nicht richtig fasst oder eventuell gänzlich fehlt.
Eventuell sind auch die Kopf-Führungsachsen nicht mehr richtig festgeschraubt?
Wenn ich die Schnecke von Hand drehe (direkt vor dem Motor is da so eine Art Stift an der Achse, mit dem man die Achse leicht drehen kann), bewegt sich ja der Kopf wunderbar hin und her wie er soll. Die Führungsachse ist auch fest. (Oder gibt es mehrere?)
Nach dem was in Wikipedia steht denke ich dass der Schrittmotor in beide Richtungen unbeschränkt drehbar sein sollte; also denke ich mal dass MacDeaths Idee dass das Gewinde "am Ende" angelangt ist nicht sein kann.
Martin
Lässt sich der Kopf auch bewegen, ohne dass Du die Schnecke drehst? (Versuch mal, wenn er vor und zurück zu schieben ist, ist etwas kaputt)
Nein, da bewegt er sich nicht.
Martin
Please post a HIGH detailled photo (and sharp) of the stepper motor + the head-slider.
Markus,
have a look at:
http://home.arcor.de/mdoege/photo/ams1.jpg
http://home.arcor.de/mdoege/photo/ams2.jpg
Martin
Humm ok.
It looks like an electronic component is bad.
Maybe an IC or a transistor.
Hard to guess.
Need to see the real hardware.
I am also not sure (actually I don't have this drive type here) if there's a plastic ring missing around the "metal nose"
Perhaps also a cable is missing as marked in the image above but I am not sure, too, here.
I also don't know this particular drive, but most drives have a switch or sensor to let the electronics know that it has reached the end position. If this is broken the motor will try to keep turning even when it reaches the end. Is there such a switch visible in the drive? If so, you should check that it's switching correctly.
Bryce.
While I was sending a PM I looked closer to the video on youtube.
Did you connect the 12v power plug?
I cannot see this.
Make sure the CPC also has 12v connected.
Quote from: Morn on 19:18, 10 July 10
Hi!
I've replaced the drive belt on my 6128 and the disk spins up OK, but it looks like the read/write head doesn't move. It just makes a buzzing noise when you do e.g. a "cat" with a disk in the drive:
http://www.youtube.com/watch?v=DX1DN0Jaz0Q (http://www.youtube.com/watch?v=DX1DN0Jaz0Q)
So, is the motor broken? But then why does it hum like that?
I can move the read/write head by hand by turning the metal rod on the right, so there doesn't seem to be anything in the way.
Martin
Does the CPC eventually give a error message?
Does the red light go on/off on the drive like the cpc is trying to read?
It seems that the drive is trying to step to the next track but the head is not moving. The CPC then tries to read the disc and verify the location of the head, and then performs it's normal error retry process.
The basic retry process is that it will seek to drive 0, then to the track and try a read. If this fails it seeks to track 39, then back to the track to try again. it repeats this over and over and over and eventually gives up.
So, it's like the stepper is not engaging and moving the head. almost like the stepper is dead, or not enough power.
12 V is connected, but maybe I should measure output from the monitor to make sure the voltage is as it should be...
I'll also check out what the LED is doing.
Martin
So, the LED is always dimly lit, even when there's no disk in the drive. I don't remember if that's normal for the CPC or not.
When I enter "cat", the disk drive spins up, then the head starts humming, the LED flickers a little (sometimes it's brighter and sometimes darker than average).
After perhaps 15 seconds or so the command terminates with "Bad Command"! Not the usual read error, retry, ignore, cancel.
Martin
P.S. I've also measured the monitor 12 V source with a multimeter, it's 12 V all right.
Well from what i told, it is probably not that, but I had such case...
Disk error missing because no Belt...
change the belt : still don't work...
I simply turned a "little bit" the endlessscrew "back"...and it worked again.
Just is, no need to turn it completly bach and forward.
Just to "unblock" the jamed mechanism...
That's all.
Also Bitte... try to translate your Deutsch...Google translator is somewhat...not that efficient...
Quote from: MacDeath on 17:57, 12 July 10
Well from what i told, it is probably not that, but I had such case...
Disk error missing because no Belt...
change the belt : still don't work...
I simply turned a "little bit" the endlessscrew "back"...and it worked again.
Just is, no need to turn it completly bach and forward.
Just to "unblock" the jamed mechanism...
So do you mean: move the screw back and forth a bit
with the r/w head attached to it or move the r/w head out of the way first?
Quote from: MacDeath link=topic=1114.msg11091#msg11091 date=1278953849
Also Bitte... try to translate your Deutsch...Google translator is somewhat...not that efficient...
Sorry for that. Of course it was Markus who introduced German into this thread. How devilish of him! :)
Martin
Btw, I do think that the led is dimly lit when the drive is idle...
Yeah, the LED should always be a little bit lit, even with no disk in the drive.
After reading through the posts again, I'm not sure we've really understood the problem. So here's some questions:
Does the disk spin when the buzzing sound can be heard?
Has the drive head ever moved?
Does the "endless screw" turn but the head stays in the same place?
At the moment, I really think the "endless screw" is just jammed, it should be covered in grease, so that the head can smoothly slide along it's threads, but this has probably dried up over the years. I'd suggest putting some Vaseline or similar grease on the "endless screw" and then manually turning the screw until the head has travelled the full distance of the screw to make sure it's properly spread. Then try the drive again.
Bryce.
B.t.w. the real name for the "endless screw" is a worm drive.
Quote from: Bryce on 10:36, 13 July 10
Does the disk spin when the buzzing sound can be heard?
Yes. You can hear the disk spinning up in the video. And I also wrote in the first post, "the disk spins up OK".
Quote from: Bryce on 10:36, 13 July 10
Has the drive head ever moved?
Not visibly and great distance, but obviously since it's buzzing, it does move back and forth a little bit to create the sound.
Quote from: Bryce on 10:36, 13 July 10
Does the "endless screw" turn but the head stays in the same place?
No, when I turn the worm drive screw by hand, the head moves as it should. And it moves easily (as I wrote in the FP, "I can move the read/write head by hand by turning the metal rod on the right").
The mechanics seem to be fine, but somehow the motor doesn't work. FP: "So, is the motor broken?" Of course I could try a little more oil, I suppose it can't hurt.
Martin
It definitely seems that the worm drive is broken because you can turn it and the head moves.
Or maybe a bad connection to the worm drive is here causing it to make the head vibrate.
Hmmm, ok, if the oil doesn't work, then it's time to remove the motor, dis-mantle it and see why it's not turning as it should :( Fiddly job, and if anything mechanical is broken, then I doubt it will be repairable. Time to look for a new motor perhaps.
Bryce.
Markus has kindly offered me to send him the drive so he can try to repair it. I think that's what I'll do, because my impression is that it's either the motor blocking somehow or the stepper motor controller malfunctioning. Either way, a replacement part is probably necessary.
But first of all I'll drench it all in olive oil and see what happens. If it doesn't do anything else, it will at least make the drive smell delicious. :)
Martin
May I suggest the "Extra Virgin Peloponnese from 2008", cold pressed of course. It has a beautiful aroma and it's dark texture will go a treat with the CPCs grey casing.
Bryce.
Um... While Peloponnese oil is just great (my girl is from there, we get lots of free olive oil each year, and we're owners of olive fields too!), I'll say it once again - olive oil is really, really bad. Try using it on a door hinge and see the muck that starts building up in a while, then try to envision your electronic equipment in its place... Also, old olive oil doesn't smell nice, so it's a lose/lose proposition :D
PS Bread with olive oil... mmmmm...
Agreed. I definitely wouldn't use olive oil (even the good stuff) as a lubricant, the bits that make it taste nice are also the bits that make it into a sticky gunk over time. I'd stick with something purer like pertoleum jelly (Vaseline) or similar as I suggested earlier and leave the olive oil for your taste buds.
Bryce.
@Gryzor: I'm also a big Olive Oil on bread fan, but I have to confess, I usually buy Italian, sorry :(
Well, you may be interested to know that there's a big scam that has been running for many, many years: Italian producers have been buying Greek olive oil in bulk and cheap and then reselling it as italian produce, premium and expensive...
Anyway, back on topic, you *can* use olive oil as lubricant in emergencies, but you have to make sure you clean it well afterwards and rather sooner than later. Alcohol can do the job.
Still not On-Topic... There's always alcohol involved when I'm enjoying some Olive Oil and Bread, usually a good Red Wine.
But back to the disk drive, send it to Markus and let us know how it goes...
Bryce.
Quote from: Bryce on 09:58, 14 July 10
Still not On-Topic... There's always alcohol involved when I'm enjoying some Olive Oil and Bread, usually a good Red Wine.
But back to the disk drive, send it to Markus and let us know how it goes...
Bryce.
Are you suggesting the drive should be taken to a restaurant for some posh nosh?
That'll make it happy and it'll work?
;)
Well it works for me :)
Bryce.
Der Stepper-Motor ist fusch!
TFM is telling the truth. I thought that too. I think the stepper motor is faulty. (Kannste wegwerfen - diesen Typ Laufwerk hab ich noch niemals nie wieder repariert bekommen - ist das schrottigste überhaupt. Am besten ist die erste Generation 3 Zoll Laufwerke, die sind noch reparabel). RIP
Kindly Regards
Tom
Quote from: Pentagon on 08:04, 17 July 10
TFM is telling the truth. I thought that too. I think the stepper motor is faulty. (Kannste wegwerfen - diesen Typ Laufwerk hab ich noch niemals nie wieder repariert bekommen - ist das schrottigste überhaupt. Am besten ist die erste Generation 3 Zoll Laufwerke, die sind noch reparabel). RIP
Kindly Regards
Tom
Thanks for the hint with the first generation, think the Plus drives are the worst.
Also, einfach mal auf ebay für Nachschub sorgen, wenn der Preis passt.
Thanks TFM, that's what I was thinking too. Would it be very difficult to find a similar stepper motor e.g. at conrad.de? They have quite a selection, but I'm not sure what to look for in terms of the specs. The 6128 service manual was not helpful in that respect.
Martin
Finding a replacement may prove difficult. For a start it's going to have to have identical dimensions and fixing points, on top of that it will need to be the same type (uni- or bipolar ie: 4,5 or 6 pole), not sure which type the cpc used. Then the steps per rotation (step angle) has to be correct. That's an awful lot of factors, that all need to be fullfilled, otherwise it won't work.
Bryce.
Quote from: Morn on 17:20, 19 July 10
Thanks TFM, that's what I was thinking too. Would it be very difficult to find a similar stepper motor e.g. at conrad.de? They have quite a selection, but I'm not sure what to look for in terms of the specs. The 6128 service manual was not helpful in that respect.
Martin
I don't know... However, a used drive from ebay or (better) another CPC user should be as cheap as ;-)
Quote from: Pentagon on 08:04, 17 July 10diesen Typ Laufwerk hab ich noch niemals nie wieder repariert bekommen - ist das schrottigste überhaupt. Am besten ist die erste Generation 3 Zoll Laufwerke, die sind noch reparabel).
I happen to have one of these with an SMD transistor (pre-stage motor driver I guess) that literally blew up many years ago, damaging a minor section of the PCB traces below it. By the time I'd figured out the code of the exact replacement (as the original had crumbled to dust along with its markings), the spare had been discontinued (and parts such as these were impossible to source anyway before the likes of RS-Components.com came online).
As this 3" drive is known to be mechanically intact, would one of you experienced in this type of repairs like to have a go at soldering in a new transistor and see whether any other components need replacement (as the damage looks like from a power surge), or whether it could at least be combined into a working unit with another broken one?
Might even have a chance to personally take the drive to someone in the Munich area (which seems to be have a cluster of CPC survivors ;)) next month...
Hi OCT,
I could take a look at it, but maybe you should send a picture of it first. When a transistor blows up, it's rarely the transistor that was broken, rather something else failed causing the transistor to short and then explode. Or was there a known power-surge / short-circuit that caused the transistor to bid farewell to life as we know it?
Bryce.
Quote from: Bryce on 08:38, 21 July 10but maybe you should send a picture of it first [...] was there a known power-surge / short-circuit that caused the transistor to bid farewell to life as we know it?
Scrolls from the era recently unearthed by IT archeologists tell that a flash of light was seen from the TV set the CPC had been connected to, and which turned itself off while an infernal odor protruded from the CPC (the mainboard of which survived the incident unscathed, unlike its disk drive). When the tribe's medicine man opened the CPC, broken fragments of the transistor were found beneath the drive assembly, revealing an inscription that must have read "Y-D".
Has the hallmarks of an overvolt issue in my book, from the mains or aerial, if we are to discard Däniken's standard explanation that it must have been an attack by ancient alien astronauts. ;)
Since those by-gone days, we have advanced our understanding and knowkledge of the CPCs inner workings (and have the schematics to prove it). And despite underlying fears that this might anger the 8-bit Gods, I suggest we awaken the drive from its Cryogenic Suspension and breath new life into it. It's a brave step into the unknown, but one we must take...
Bryce.
B.t.w. Do you know which transistor bit the dust?