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Open Bench Logic Sniffer / Re: Board unresponsive
Here is what happened (sorry, not allowed to post full links yet):
After my OLS arrived, I went through installation according to site linked from seeedstudio (although the project page link in Seeedstudio product description was outdated, and thus I followed on to gadgetfactory page first steps).
The drivers and software were installed and worked correctly first time: the device enumerated as COM4, successfully connected to client, and acquired zero data using ols-0308 package and Jawis-OLS-client executable. After this, I tried self test procedure according to the Self Test Mode video at gadgetfactory. At this point, OLS client crashed on my PC, and OLS device disappeared. Since then, the device is not recognized as an USB serial device when connected. LEDs also light differently (PWR: constant green, other lights off - ACT, ARM,TRIG are never lit). Measuring power rails using an oscilloscope on the OLS board: 5V, 2V5, and 1.2V (VR3) are within spec, but 3V3 supply (at VR1 out) is constantly at 1.8V. It seems to me that neither the PIC nor the FPGA can start due to this power failure. I also measured the IDE ribbon cable used in self-test and assured that there were no short-circuits caused to the device: side-wing pins were connected to main wing pins one-by-one, respectively (GND,0,1,2,3,...15,GND to GND,16,17,...31,GND). I took extra care not to ground any of the pins while testing.
The VR1 is not hot, so I think it is neither short-circuited, nor in thermal shutdown state. Vin and EN pins are at a stable 5V input from USB Is there any other realistic situation when VR1 Vout can be around 1.8V besides the regulator chip being faulty?
Based on the above, can I expect that replacing VR1 will solve this issue? I hesitate to try this as I expect that warranty applies, but would be glad to do further diagnostics.
Any advice is welcome.