HP-21MX bootstrapping?

On 23 Feb 2008 at 0:29, Tim Riker wrote: I thought I was closer than that -- I had written, "Perhaps the ribbon cable from the front panel to the CPU is bad." :-) Digi-Key may have a complete replacement cable; I'll have to look at my 2108B on Monday when I get to work. But, from memory, the cable has a 50 pin IDC edge connector on one end and a four-row IDC "transition" connector on the other that's soldered into the board. Part number C3PET-5006G-ND might be it. But you'd have to unsolder the 50-pin transition connector from the front panel PCB. It'd be easier to cut off and replace the edge connector, I believe. The OEM part for the edge connector is 3M part number 3415-0001. Very unlikely to work, I'm afraid. Those are pretty much one-time assembly connectors, and I've had very poor luck in separating the two parts of the connector, removing the old cable bit, and reusing it. Nine times out of ten, I'd wreck the connector in getting it apart (most often, I'd wind up pulling one of the IDC pins out with the cable bit). Much better to try a new one. On 23 Feb 2008 at 8:17, Glen Slick wrote: I think that's the way to go here. I'll second that. With an arbor press and mandrels designed for to receive the connector halves, it goes together easily. If you have to use Vise- Grips, it's quite difficult. A bench vise with smooth jaw faces is a bit better if you do things slowly and carefully and ensure that the parts and the cable line up correctly as you squeeze them together. It takes quite a bit of force to punch through 50 conductors simultaneously. -- Dave