Prepare wiring diagram for gadget.
Check against the connection-list spreadsheet the last guy used in place of a diagram.
Check both against the previous unit. Update to match.
Assign color codes to all wires, the better to keep things straight.
Assemble connectors with pin 1 facing away from the technician when the diagram, if held such that color names are right side up, has pin 1 facing toward the technician.
D'OH!
Well, I may not have damaged anything. And the only thing plausibly damageable by this goofup (apart from my reputation) is one for which there's a spare on hand.
This has nothing to do with the software problem, though. That's a FUBAR unto itself.
And I'm sure by now the client is really glad this is a fixed-price contract. (Not that the time to fix something like this would go on my timesheet anyway, except as annotation.)
I used to work at a large minicomputer company located in Maynard. We did the same thing once.
The prototype board came back with a mirror image of the pin numbering, so we had to build a batch of special adapter sockets where the chip was glued on upside down and all of the pins had tiny wires on them that connected to the right pin.
Posted by: Jeff Bell | Tuesday, 03 June 2014 at 14:27
Ah, the infamous mirror-imaged chip!
At least with DIPs, you could just install them from the solder side of the board. I take it yours wasn't a DIP.
I recall a couple of Fun Projects like that: one had socketed PLCCs, with goofed-up footprints such that the chips had to be installed in very tall kludged sockets with (if memory serves) swapping of inner & outer rows.
Then there was the through-hole board that came back from fab (and getting boards fabbed was a slow and expensive process in those days!) with the copper layers swapped. We cried. Then we laughed, as we realized that we could just install the components from the wrong side. Then we cried again when we remembered that it had a dual-readout edge connector, and we'd have to swap all the connections to it.
Posted by: Eric Wilner | Tuesday, 03 June 2014 at 14:39