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Looking for hp 67 cable
09-07-2023, 02:44 PM
Post: #4
RE: Looking for hp 67 cable
Do you know if the problem is an electronic failure or a break in the cable? If it is an electronic failure about the only thing that cannot be fixed is if a winding is burned out in the transformer. If there is a break in the cable that can be repaired too.

In my experience they most often break at the calculator end right at the strain relief, which unfortunately is the least convenient place for making a repair. I found that the easiest way to locate the break was to use a continuity tester and probe through the insulation with a pin. If the break is not at the strain relief on the calculator end the repair is pretty simple, if in the middle of the cable simply cut out the damaged part and splice the ends back together. If the break is transformer end it is easy to clip off the damage and reconnect inside.

I the damage is at the calculator end surgery is required. The way I did it is to cut in just below where the connector widens, if you are careful and cut from the end toward the strain relief you can leave if as a flap that you can glue down when you are done and it will look a little neater, you can get an idea where I cut from the picture below.


After opening up the connector you will need to remove material to get don to the top of the pins. I had cut the broken cable just outside the strain relief and pull the bits of wire out of the strain relief, you may need to insert a tool in between the wires and the strain relief to get them out.

At this point I also put a couple pieces of heat shrink onto the cable. One piece small enough that it will shrink tightly to the cable. and a second piece, slightly shorter, and just large enough to fit over the strain relief.

Next thread the cable in through the strain relief and solder the ends to the pins. Before you proceed make sure your connections are correct.

Once you are sure the connections are correct, the next step is to fill the area gouged out to expose the top of the pins, I filled the space with UV epoxy but regular epoxy of even Silicon sealer would work too.


Next glue down the top I used contact cement to glue this down. The last thing I did was slide the smaller diameter piece of heat shrink up to the strain relief and apply heat to the end nearest the strain relief so that when it shrinks it remains in contact with the strain relief. Once that piece is shrunk down slide the other piece up over the strain relief and apply heat to shrink. The idea of the heat shrink is to provide extra strain relief to hopefully help with the cable bending sharply and also if the cable does break again, it will break further out and be easier to repair the next time.


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Messages In This Thread
Looking for hp 67 cable - ThomasWendl - 06-06-2023, 01:24 PM
RE: Looking for hp 67 cable - arf - 09-06-2023, 07:43 AM
RE: Looking for hp 67 cable - rprosperi - 09-06-2023, 11:09 PM
RE: Looking for hp 67 cable - Paul Berger (Canada) - 09-07-2023 02:44 PM

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