We’ve got the PreSonus Inspire 1394 with symptom that sounded like “It was a kind of working and now it seems a kind of not working”.
It was exposed to some tests investigating operation of the following card’s modules: power circuits, connectors, DAC/ADC, DSP, FireWire interface. An important role in tests had our beloved 4-channel oscilloscope, sweet Linux kernel logs (dmesg), common sense and lifetime experience. Here are the card’s photos:
For conscience’ sake, results of tests were described in details and sent to PreSonus tech support asking for any technical documentation for the card. Their first answer was to try to reboot the computer :), the second was to send device to service center to USA. As a whole, we didn’t get any useful (technical) information from the support. That was very sad, so we kept on testing. As a result we supposed that problem is related to FireWire interface chip TSB41AB2. This chip was kindly provided by Texas Instruments Inc. and delivered directly to our office. On the photo below you can see burnt chip cut-off from the PCB:
And here is the new one:
PCB with the new chip installed:
The patient is now safe and sounds well. Thanks to Linux kernel developers for kernel functionality. Also we disapprove PreSonus and lots of other hardware manufacturers for the closed architecture of their devices.