🚀 go-pugleaf

VanguardLH wrote:
> ClueLess wrote:
>
>> Posted to comp.sys.ibm.pc.hardware.storage, 24hoursupport.helpdesk
>>
>> Hi Friends
>>
>> Here is a strange problem, when I connect my hard disk using the 80
>> wire cable my computer does not recognize it.
>>
>> It happened this way. I had to check another hard disk and so I
>> swapped the disks (IDE0) and found it was not recognized. Then I
>> connected the original hard disk and it was also not recognized. I
>> tried both the IDE0 and IDE1 channels with the same result. I tried
>> also other hard disks as well other 80 wire cables, still no go.
>>
>> Then I found an old 40 wire cable and when connected with this,
>> bingo, all the hard disks are recognized.
>>
>> No pins broken, no hardware damage. All the cablea are in good
>> condition. In fact the machine for years worked with only the 80 wire
>> cable.
>>
>> How does this happen? This is just a banana motherboard and the
>> problem is in the bios stage itself. (bios says "Not installed")
>>
>> If any of you can give me an explanation or a solution please do

> Signalling wise, there is no difference between a 40- and 80-wire IDE cable.

Wrong. 80 wire cables are usually cable select cables, 40 wire cables usually are not.

> Only 40 signal wires are used in both.  The 80-wire ribbon
> cable has a ground wire between each signal wire to reduce cross-talk
> and noise.  It is still a 40-pin connector to a 40-pin connector setup.

But isnt identical on the cable select question.

> There are some cables that are physically altered (by snipping out a
> very short length of one signal wire, or not connecting that signal
> to the connector pin, or with a missing connector pin) to make them
> "cable select" cables.  Rather than you configuring your drives as
> master and slave, you configure both to "cable select" and the lack
> of the signal from controller to one of the drives makes it the slave.
> Unless you using a meter to test each pin of the 40-pin
> connector at the mobo end to each matching pin in the other 40-pin
> connectors to see if all have continuity or if one is open, just test
> using a different 80-wire, 40-pin IDE cable.

That doesnt explain why the original drive isnt seen anymore.

> It's also possible that the 80-wire, 40-pin cable is damaged so one
> of its signal lines is disconnected.  Just because it worked for
> years doesn't mean it was a perfect cable.  The connector's pins
> aren't soldered to the wires. The ends of the connector's pins are
> simply split to scissor through the insulation to make contact with
> the wired by squeesing the two tangs against the wire.  It's a
> mechanical connection.  This is how, for example, a Scotchlock
> splicing connector works.  It isn't the most secure or durable
> connection.  Also, you pulling on the ribbon cable to remove the
> cable can cause damage, especially if you wiggle from side to side to
> waddle the connector off the header.  That's why the better cables
> come with a nylon or plastic pull tab that is part of the connector
> assembly and you pull on that rather than the ribbon cable.

> You never mentioned if the connectors were polarized.  If the
> connector has no tang (to slide into a matching notch in the shroud
> around the header pins) or doesn't use a blank pin 20 (a solid spot
> where pin 20 would be but with no hole for a pin to slide into), or
> the shroud around the headers is depolarized by having notches on
> both sides, or the shroud is missing, it's possible you attached the
> connector upside down.  It's also possible you didn't slide the
> connector all the way onto the header pins.  It's also possible one
> of the female pins inside the connector is loose and didn't make good
> contact.  Did you ever try a different 80-wire, 40-pin cable?