Pardon me for re-opening this thread, but after a couple of hours searching it is the only source of occurrences similar to the one currently plaguing me (and my Panther). If I leave the machine running and turn my back for a time (variable: one half hour to several hours) it hangs, showing the hard drive access light continuosly on and with no response from the mouse (pointer or buttons) or keyboard. That is, a total inability to terminate any application or shutdown by any means other than the power rocker switch at the back of the machine, on the power source. When doing that, I noticed that a minimum interval of about 30 seconds in the "Off" condition was necessary to avoid the machine starting up the Boot sequence immediately on moving the rocker switch to "On" ! Reading the previous contributions to this thread did not make it clear whether the experience of others included the occurrence of hanging during an extended period of rest. Rest is a relative thing. I suppose you might say that the screensaver settings might be a factor. If so, they are: "Type" - DPMS; "Blank delay" - 5 min.; "DPMS state ... " - Monitor on stand-by (DPMS level 1); "Unblank on screen writes" - NOT ticked. If all the above fits with previous experiences, is it really the case that it is due to deterioration in the power supply output values? If so, is it really critical to seek to stay below the top of the range quoted by JWB in this thread and elsewhere (Message-ID: <c3cd1a4f4e.jbwork@xxxxxxxxxx> ) ? OK, now for the confessions. Still on 5.10, USB 2. What else do you want to know? The OS version does not seem relevant to this problem. It has only arisen in the last 2 weeks during which time no new software has been introduced. If you want to know the voltage, please specify clearly: the running conditions and the recommended contact points. Regards. Frank. -- Frank Watkinson. email: <frank@xxxxxxxx> Using !Pluto 3.04c on Iyonix 5.10. Still RPC-SA (4.39 Adjust) for some things. --- To alter your preferences or leave the group, visit //www.freelists.org/list/iyonix-support Other info via //www.freelists.org/webpage/iyonix-support