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General Category => Amstrad CPC hardware => Topic started by: Bryce on 21:43, 03 December 12

Title: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 21:43, 03 December 12
This is probably one of the most frequently asked questions here in the forum, so I thought I'd make a short guide to address it...

Chances are, you've lost the write-pin while you were changing the belt. It's a small metal pin that senses the position of the write-protection tab on the inserted disk and if it's missing all disks will seem to be write-protected to the computer. But before you go crawling around aimlessly on that patterned carpet, here's what you are actually looking for:

[attach=1,msg53898]

Yes, it's small. If you do find it, this is where it needs to go. It simply drops into the hole. If no disc is inserted at the time, it should go all the way in until the head is lying against the aluminium frame:

[attach=6,msg53898]

However, this might not be your problem. There are several versions of the Amstrad 3in drive and not all of them used a physical pin, some used optical sensors. So how do you tell if your drive had a pin in the first place?
If your drives PCB has a black sensor like this one:

[attach=2,msg53898]

Or a plexiglass sensor like this one:

[attach=3,msg53898]

Then stop crawling around on your hands and knees like an idiot, your drive never had a pin, so you haven't lost it.

If however, your PCB has switch contacts that look like this:

[attach=4,msg53898]

Then keep looking, you really have lost it. If you still can't find it, then your only option is to make a new one. This is what you'll need to make:

[attach=5,msg53898][/attach][/attach][/attach][/attach][/attach]
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Gryzor on 14:56, 04 December 12
Great guide!  Love the detail you went into, right down to the diagram. But why not in the wiki?
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 15:34, 04 December 12
I was a bit worried about uploading anything to the Wiki at the moment, due to the issues with the updates. If the Wiki is deemed stable again, I'll copy the whole thing over tonight.

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Gryzor on 15:35, 04 December 12
The wiki is never unstable. When it's down, it's down for good. That's what the updates were there for anyhow :D

But yes, I understand. It's release-level again.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 13:44, 10 December 12
Transferred to the wiki. It can be found here (the article, not that pin that you've lost!): Writepin - CPCWiki (http://www.cpcwiki.eu/index.php/Writepin)

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: MaV on 13:56, 10 December 12
Quote from: Bryce on 13:44, 10 December 12
Transferred to the wiki. It can be found here (the article, not that pin that you've lost!): Writepin - CPCWiki (http://www.cpcwiki.eu/index.php/Writepin)
Perfect!

I think the article has answered the pin problematic for good (even for the drives that don't have one)! :)
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 14:15, 10 December 12
Luckily, I own all types of the drive, so other than having to disassemble them all, it was just a matter of taking pictures. But at least from now on, when the next "Why is my drive read-only" question comes, we can just point them there instead of going through the whole thing again :)

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Gryzor on 15:44, 11 December 12
Awwww that's awesome, you deserve a gold star!


[attachimg=1]
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 15:56, 11 December 12
Oooo, I'll print it out and stick it on my forehead :)

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Gryzor on 16:13, 11 December 12
No, you silly, that's for you to stick on your NC200!
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 16:21, 11 December 12
I don't own an NC200, can I put it on my Tandy 102 instead?

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Gryzor on 16:32, 11 December 12
Ah, you're one of those kids, using their older and equally poor big brother's books, aren't you? :D

Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: spookspring on 23:38, 14 March 13
Hmm shouldn't you mention precision cleaning the roller heads, looking for loose wires, bad fuses and loose connectors?
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: TFM on 16:39, 15 March 13
Thanks' for that GREAT guide Bryce!!!  :) :) :)
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 11:02, 16 March 13
Quote from: spookspring on 23:38, 14 March 13
Hmm shouldn't you mention precision cleaning the roller heads, looking for loose wires, bad fuses and loose connectors?

Well it's not really meant to be a complete guide to fixing the drive, more of a guide for people who lost the write-pin, which seems to be a common occurance. What are roller heads??

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: beaker on 12:02, 16 March 13
Quote from: Bryce on 11:02, 16 March 13
What are roller heads??

Hopefully nothing like what popped into my head....  :o

[attach=2]
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 13:27, 16 March 13
That's you isn't it? :D

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: TFM on 20:44, 16 March 13
No, that Spookspring, because he knows them. I may be wrong though ;-)
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: zeropolis79 on 14:35, 23 February 14
Has anyone got one of these pins they would sell me please? I've checked my drive and it is missing the pin..

Many thanks!
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: AMSDOS on 02:00, 24 February 14
Would it be easier to find the Pin with a Magnet instead of getting down on hands and knees?
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: AxelStone on 13:16, 29 April 17
You are a wise man: just changed my ribbon and I've a read only drive because I didn't know was that small pin  ;D . I need to open it again and place it. Thanks!
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: Bryce on 11:33, 01 May 17
I knew this thread would help someone eventually. :)

Bryce.
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: ||C|-|E|| on 14:42, 01 May 17
I akso had the problem looong ago, before internet. It was a bloody nightmare to realize what was happening! I was almost ready to give up when I found the pin  :picard:
Title: Re: Help, I changed the drive-belt and now my disk drive is suddenly read-only?
Post by: SerErris on 16:29, 19 February 22
Has anyone found a source for those pins?

I checked with the measurements, and the closest I could find was this:


https://www.ebay.de/itm/324715569305?chn=ps&norover=1&mkevt=1&mkrid=707-159967-267642-0&mkcid=2&itemid=324715569305&targetid=1597449508726&device=c&mktype=pla&googleloc=9044552&poi=&campaignid=15996660938&mkgroupid=138217480928&rlsatarget=pla-1597449508726&abcId=9300802&merchantid=114684840&gclid=CjwKCAiAx8KQBhAGEiwAD3EiPzkxvgpFJHXWXAe0F_t3aG9sDv49q5hZawV3Rb7VY_WtKHAveCf7bhoCd2cQAvD_BwE (https://www.ebay.de/itm/324715569305?chn=ps&norover=1&mkevt=1&mkrid=707-159967-267642-0&mkcid=2&itemid=324715569305&targetid=1597449508726&device=c&mktype=pla&googleloc=9044552&poi=&campaignid=15996660938&mkgroupid=138217480928&rlsatarget=pla-1597449508726&abcId=9300802&merchantid=114684840&gclid=CjwKCAiAx8KQBhAGEiwAD3EiPzkxvgpFJHXWXAe0F_t3aG9sDv49q5hZawV3Rb7VY_WtKHAveCf7bhoCd2cQAvD_BwE)

That is 1mm nail with a 1.4mm round head and it is 12mm long. So if you cut the pointy part of it, it should be perfect in length and width, but I am not sure if the head is wide enough.

Anyone found something better?


My current workaround is a pin from a pin-header, where I bent the top of the pin to make it stick in the hole. So I think the 1.4mm should be fine, because it prevents the pin from falling through the hole.
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