+5V Pins on 6733 gone for good?

[AirMastah]

I just recently purchased a couple of 6733 D/A cards, and had an unfortunate accident where two of the pins on one card (Pins 1 and 2) bent and shorted to the card case. After repairing the pins, I found that everything functions on that card, except that the +5V pins now show +1.6V instead. Further, after removing this card and replacing it with a spare (in a different PCI slot on the same machine), the new card functioned perfectly the first time the system was rebooted, but then lost functionality on the two +5V pins completely. Plugging the new card into a different machine entirely did not restore the +5V pins.

The digital and analog outputs on both cards still function flawlessly, so I'm assuming this problem is related to the internal system "fuse" that is supposed to automatically reset when a ground fault occurs. I've gone back and tested the PCI bus both of these cards were plugged into with an oscilloscope, and the voltage levels on all of the PCI pins seem normal (+12 where +12 should be, +5 and +3.3 where they should be, no floating ground voltage)...

Any thoughts on what could've happened to these cards, particularly the new one? Further, is it possible to force a reset of the fuse on these cards?

Thanks!

[Ryan-C]

Hi there,

Unfortunately, as you describe it, the card would need to be sent in as an RMA to fix those +5V's.

When it was shorted, a large current must have damaged the fuse and/or the voltage regulator.  I am fairly confident that it is the voltage regulator rather than the fuse, because if the fuse was blown then you would be getting no voltage at all.  There would be no way to replace this yourself -- we would need to taek a look here at NI in order to replace that part.

I would recommend getting in touch with the account rep who facilitated your purchase of this PCI-6733 to see what your options are for sending it in for RMA repair.

Best,

[AirMastah]

Voltage regulator is shot? That's possible... though it leads me to a couple more questions:

1. On the damaged card, I recently tried testing the digital out functionality. Despite all of the digital output pins starting at 1.6V, once the system initializes those pins and begins outputting from them, they transition to 0 or 5 volts as commanded. They appear to be capable of sourcing a load as well (voltage did not collapse when a 10kOhm resistor was connected between them and digital ground). Would this behavior be expected if the voltage regulator was damaged?

2. The other D/A card, which was in the machine at the time, still shows 0V on the "+5V" pins (pins 8 and 14, I believe). Everything else about this card appears fully functional, but even after swapping the card to a different machine, the functionality on those two pins never returned. If the overcurrent protection on the +5V pin (which was not even in use at the time) was somehow set off by being in the same machine as the damaged card, is it possible to force the "fuse" on these two pins to reset?

Thanks!

[Steven_K.]

Hi AirMastah,

The external +5V lines are connected to the PCI +5V lines with some fusing. We use a different path for the DIO voltage. It sounds like the fuse on the external +5V fuse has blown. At this point if you would like to get your card repaired, please contact us at 1-866-275-6964 to initate the RMA process.