As the manual says, it should run for a while to drain the power supply voltage to a safe level, then it simply slows to a stop. But 15 minutes is definitely "over the top" - something isn't shutting down the power supply when you tap the POWER button (typically the fan will run for 30 seconds or so, IIRC). That also means that dangerous voltage exist inside the KPA500 even with the mains plug pulled.
As with all things microprocessor or microcontroller controlled these days, the first thing to do is reload the firmware and see if that cures it. Did you build it from a kit? I wonder if having the ribbon cables that runs from the front panel board to the I/O board on the rear panel, or the smaller ribbon cable between the I/O board and the power supply module installed incorrectly might cause this, since the signaling obviously must follow that path. Ron AC7AC -----Original Message----- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Jay Sent: Saturday, July 16, 2011 1:32 PM To: elecraft@mailman.qth.net Subject: [Elecraft] KPA500 Fan Question Just did the first voltage test on #153. Basically I turned it on to check that the tap is the right one, then turned it off. The fan ran for over 15 min before I turned it on again (which shuts the fan down).... How long should it go before shutting down? Repeated the procedure and tapped "temp" and it showed 23.5 C and the fan does not run while in "Standby", but it comes on again when I tap the power button. Still running as I type. Is this adjustable? Jay, W6JDB ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
