🚀 go-pugleaf

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.
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.

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.

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?