Author Topic: Replacing the ribbon cable on a DDI-1 interface  (Read 334 times)

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Offline chrisgreen

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Hi everyone


I've managed to get hold of a DDI-1 interface (along with the matching 3inch external drive). The drive is in great condition apart from needing the usual belt replacement and goo cleanup, but the DDI-1 interface cable has seen better days.


I'm assuming it would be fairly straightforward to replace the cable with a new ribbon cable and new 34-pin IDC connectors, but what do I need to watch out for? Are there any modifications I would need to make to a new cable or to any of the new connectors? Am I right in thinking the second header on the cable has some pins missing on the lines where power normally runs back from the first 3-inch drive (to power the interface)?


I will eventually do the circuit board mod so that the interface takes power from the expansion port rather than a drive, but for now I just want to get the ribbon cable in good shape.


Thanks in advance for any help.

Offline Bryce

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Re: Replacing the ribbon cable on a DDI-1 interface
« Reply #1 on: 14:51, 14 April 21 »
The connector in the middle, not the one at the end of the cable, is the one that's missing pins. Also, there is a 98% chance that you will break the connector on the PCB while trying to remove the old cable, so it's probably worth ordering another one before you start.


Bryce.

Offline gerald

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Re: Replacing the ribbon cable on a DDI-1 interface
« Reply #2 on: 17:42, 14 April 21 »
As Bryce said, the middle connector has missing pins where the Drive inject 5V supply for the controller.
But both connector also have a missing pin on the one of the 2 drive select.
FD1 drive are wired to respond to both drive select. The actual selection is done by the cable.

Offline chrisgreen

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Re: Replacing the ribbon cable on a DDI-1 interface
« Reply #3 on: 18:01, 14 April 21 »
Got it - thanks both for the guidance.


I've ordered a couple of replacement connectors for where the cable meets the PCB inside the interface (you are right, that's going to snap as soon as I try to dismantle the connector, so better to solder on a fresh one once fitted.)


I'll come back when all the parts have arrived, as I will need to clarify exactly which pins to remove from each of the connectors before crimping them onto the new ribbon cable.


Thanks
Chris

Offline Bryce

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Re: Replacing the ribbon cable on a DDI-1 interface
« Reply #4 on: 20:43, 14 April 21 »
You don't have to remove the connector from the PCB. It's only the top cover that breaks, so you can leave the bottom half on the board and use the new cover.

Bryce.