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use de-oxit 50 spray in the card slot and do not wipe off.
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I don't understand why manufactures use card-edge connectors in mission critical equipment that often cost in excess of a quarter million dollars.
Edge connectors are doomed to fail in high stress environments. Movie projectors that need to run for twelve hours per day or longer, 364-1/2 days per year, are certainly mission critical. Given that they are required to run for so long, unattended and with little to no maintenance, I'd call that high stress.
There are plenty of other methods for connecting daughtercards to backplanes. DIN/Eurocard connectors come to mind, offhand. Give me some time to think and I can, probably, come up with a few other methods. I'd rather see electronics connected together using D-sub or Micro-D connectors. Those can be secured with jackscrews and, with silicone interfacial gaskets. No vibration or fretting. No moisture ingress or other contamination. (e.g. popcorn fumes) They'd be virtually bulletproof! Put some De-Oxit on them before assembling them and they'd last forever!
Don't give me that "can't be done" bullcrap. I make connectors like that, every day. They are waterproof and can be submerged in salt water for hours. They can survive in temperatures in excess or 400ยบ C. (The temperature at which solder melts, thus making the security of the connector, itself, a moot point.) You could remove them from the equipment they are installed in, take them out to the parking lot, run them over with your car and, if they aren't too physically damaged, put them back into the equipment and they'd still work. Some of the stuff I work on is designed to survive the EMP from a nuclear blast. I am 100% certain that connectors can be made that don't fail.
The next cry I often hear is cost. Again! Horse feathers! Digital projectors cost a quarter million! Upgrading from a $25-$50 part to a $100 part is peanuts. I'd pay an extra $1,000 for the peace of mind without batting an eyelash. Besides, what is the price of one service call? You're paying a couple-few hundred dollars for some guy to come out and spray some stuff on them and send you the bill. The money saved using cheapo components is easily recovered when you don't have to pay for service calls, not to mention lost business due to malfunctioning equipment.
It just pains me to see movie theaters being slowly choked out of business by something so simple as s six-inch long piece of plastic and some wires!Comment
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I suspect the initial choice of edge connectors was by TI. I think edge connectors can be reliable, but they need gold contacts on the board and on the connector. The connector should also have bifurcated contacts to make at least two contacts with the edge connector finger. As I recall, Eurocard connectors use a pin in socket connection. Often these make four contacts per pin, further increasing reliability. And, again, they need to be gold to handle low currents.Comment
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I agree that edge connectors can be reliable if enough care is put into their design. Yes, bifurcated contacts. Yes, gold cladding.
(Actually, gold over nickel is the standard. It keeps the underlying copper from amalgamating with the gold and causing embrittlement failures.)
Euro connectors are just one idea I thought of, offhand. I know that there are plenty of other options beside edge connectors.
The company I work for makes interconnects that are rated for aerospace and even spaceflight. We've got product that flew to the moon and is still up there, to this day. I bet that, if somebody went back there, with the right resources, they could probably still fire up the computers on the Apollo 11 lander.
Like I said in another thread, it upsets me when I (and other people like me) work hard to make things right but others don't seem to care. I get pissed off when my work is treated like garbage.Comment
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