We have had 3 Venue systems in the field that either don't want to power up or if they do power up, run for a few seconds to several hours and then shut down. Since replacing the external power supply with a different type "fixed" the problem, we suspected the external power supply. However, we were never able to get a "bad" supply" to fail. We overloaded them by 50% and heated them to 150 degrees F ambient and they merrily continued working. The answer turned out to be much simpler than the maligned power supplies.
The polyfuse is under the main cover and is about 1 inch away from the red power switch on the front panel. We have put pictures and instructions on our web site. Here's a link: Venue polyfuse. Two soldering iron tips heating the opposite pads of the polyfuse will remove it in seconds. If you screw it up, we'll still fix it at no charge.
The standard external power supply (DCR15/1A2U) for the Venue is an 18+ Watt unit and is OK to run the new Venues. The maximum power the Venue pulls with six VRS's or VRT's is 16.5 Watts. In testing, we have overloaded the standard Venue power supply to 25 Watts for 2 hours and it was fine. We will load the supply to even higher levels and also run it at high loads in the oven to just be sure that it isn't a part of the problem. (The tests after this was first written show the supply delivering 37 Watts at room temperature and 24 Watts at both 150 degrees F. and at 90 Volts line voltage input.)
This fuse overload would explain why checking the external supply always shows the supply to be good. The reason substitute supplies "fixed" the problem is that if a substitute supply has slightly higher voltage under load, the current demand from the Venue will be less and the fuse would then be OK. Remember, the fuse is right on the edge of working or not.