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geekhack Community => Keyboards => Topic started by: chyros on Mon, 25 May 2015, 18:59:32

Title: broken Model M cable
Post by: chyros on Mon, 25 May 2015, 18:59:32
One of my two Model M PS/2 cables (the SDL type) lost two of its pins (on the PS/2 part) a while ago. I've got a few other PS/2 cables lying around and I was wondering whether it was possible to somehow put the head of another cable onto this one, which I guess should be possible, right? Could anyone tell me what to do exactly? I haven't taken the head off the cable yet out of precaution. Cheers!
Title: Re: broken Model M cable
Post by: reset on Mon, 25 May 2015, 20:37:10
Some PS/2 cables only came with 4 pins. (Two of the pins don't seem to have a function.) It may be that the "missing" pins were never there in the first place. Google "PS/2 pinout" to see if the unused pins correspond to what's missing. If that's the case with yours, it will work fine.
Title: Re: broken Model M cable
Post by: fohat.digs on Mon, 25 May 2015, 20:59:05
It shouldn't be too hard to figure if you have a multimeter.
Title: Re: broken Model M cable
Post by: chyros on Tue, 26 May 2015, 03:21:37
Looks like it's pins 1 and 5 that are missing. Which sound somewhat critical.

So do I just shop off the end and reconnect it to another head? In what way do I use the multimeter for it?
Title: Re: broken Model M cable
Post by: fohat.digs on Tue, 26 May 2015, 08:15:58
Looks like it's pins 1 and 5 that are missing. Which sound somewhat critical.

So do I just shop off the end and reconnect it to another head? In what way do I use the multimeter for it?

First, remember that you are looking at the socket and not the plug in the diagram. Everybody makes that mistake.

Second, can you tell which wire is connected to which pin?

Third, "Fohat's Rule":

NEVER  TRUST  COLOR !
Title: Re: broken Model M cable
Post by: greath on Tue, 26 May 2015, 08:19:08
If you can't fix it you could always buy a new one: http://www.clickykeyboards.com/index.cfm/fa/categories.main/parentcat/9417
Title: Re: broken Model M cable
Post by: chyros on Tue, 26 May 2015, 12:28:24
Looks like it's pins 1 and 5 that are missing. Which sound somewhat critical.

So do I just shop off the end and reconnect it to another head? In what way do I use the multimeter for it?

First, remember that you are looking at the socket and not the plug in the diagram. Everybody makes that mistake.

Second, can you tell which wire is connected to which pin?

Third, "Fohat's Rule":

NEVER  TRUST  COLOR !
Wait, so it's actually 2 and 6 I'm missing? Oo
Title: Re: broken Model M cable
Post by: nubbinator on Tue, 26 May 2015, 12:42:32
Or, instead of worrying about all of this, you could just pick up one of the SDL to USB cables on eBay.
Title: Re: broken Model M cable
Post by: Snowdog993 on Tue, 26 May 2015, 13:46:19
Wait, so it's actually 2 and 6 I'm missing? Oo

Then it should work just fine.  You may need an active PS/2 to USB adapter, if you don't have one already.
Title: Re: broken Model M cable
Post by: chyros on Tue, 26 May 2015, 16:48:22
Or, instead of worrying about all of this, you could just pick up one of the SDL to USB cables on eBay.
I have two cables and one Model M left so I don't need it. I was just wondering if I could fix it, as a backup.

Wait, so it's actually 2 and 6 I'm missing? Oo

Then it should work just fine.  You may need an active PS/2 to USB adapter, if you don't have one already.
Cool, cheers! I'll try it out next time.
Title: Re: broken Model M cable
Post by: berserkfan on Wed, 27 May 2015, 07:46:28
'
Third, "Fohat's Rule":

NEVER  TRUST  COLOR !

This is a 100% correct rule. That said, I really hate it. I wish international governing bodies should all get together and agree that red means power and black means ground and that anyone who refuses to produce to that standard should not be allowed to export his electronics.
Title: Re: broken Model M cable
Post by: chyros on Thu, 28 May 2015, 13:41:00
It works! Good thing I hadn't chopped off the head yet xD . It probably didn't work at first because I'd tested it with a cold start, which doesn't work on a non-native PS/2 port, I later found out. Cheers guys!