pxi controller 8186

[vesko]

I have a PXI-1042Q chassis with a PXI-8186 controller. Most of the time the controller does not boot: the LED on the "on" switch does not light or lights for a fraction of a second, no lights on the 8186 come on. Intermittently, the switch LED would come on and the 8186 would boots normally and work fine until I switch it off. With the controller out of the chassis, all voltages are present on the backbone board as specified. If other card (ZT410PXI) is present in the chassis, it lights up "Ready" even though the controller does not boot and the LED on the "ON" switch does not come on. Is this a problem with the controller or with the backbone?

[Beutlich]

It is hard to say without being able to swap out the controller/chassis with other controllers/chassis. However, the chassis seems to operate without the controller as you would expect the chassis to function without a controller. This might still be a chassis issue if it is not able to provide enough power for all of the devices, but I would guess the controller if I had to guess. You could try powering on the chassis with only the controller, and if it worked reliably with only the controller than that would indicate the chassis, otherwise it is still unclear. If you have a service contract, you should consider calling NI about the device.

[vesko]

Thanks. I of course tried the controller alone, makes no difference. As I mentioned, all the correct voltages are present on the monitor connector while 8186 not booting. My feeling is the part driving the LED of the power switch (i.e. the one that decides if the power supply voltages are o.k.) is at fault, but I have no idea whether it is the controller or the chassis' logic. And when the 8186 (occasionaly) boots up, it can run (with other boards in the chassis) for hours with no apparent problems.

[vesko]

Some development: It appears that this is a temperature issue, which I kind of bracketed to the NI's "Fan Interface Board" in the chassis' power supply module. The switch's LED is directly driven by a NI-specific FPGA on that board, which is next to a 7805 regulator with no radiator. I found out that the 8186 boots ok when the chassis has been unplugged for about 15 minutes, while no amount of waiting will make it boot if the mains plug is left in the wall. This seems to indicate a heat problem, and the most likely source is the 7805 and neighboring FPGA. I guess I'll have to live with unplugging the chassis each time I switch it off.

[Beutlich]

You should call 1-866-ASK-MY-NI (866-275-6964). The chassis sounds damaged, so we can talk about repairing or replacing the device once we are on the phone.