Hi all, SKA-SA have suffered a number of ROACH2 power supply failures. After investigation we determined that the power supplies (ISTAR TC-20FX2) overheat and then fail. This is due to obstructed airflow and fan failure. The front air intake of the ISTAR is almost completely blocked by the wire loom, and the fan is of the sleeve bearing type. In all the failed power supplies the fans had seized.
One workaround is to set the ROACH2 enclosure fans to maximum, this will force some air through the power supply. Our failure rate dropped significantly after setting the fans to maximum, but we still encountered failures. This can be done by commenting out the following line in /etc/tcpborphserver3.init: #?job process r2fanctrl exec://r2fanctrl We have identified another power supply by FSP (FSP250-60FAG). We have not had any failures using this supply and more than 50 boards have been running for 3 months. The supplies do not have the correct mounting holes, so fitting them is an issue. We have used thin double sided tape, but this will not be sufficient if the LRU is to be transported. If you have any questions do not hesitate to contact me. Regards Alec Rust SKA-SA
