[Elecraft] [KPA1500] Odd power up behavior

[Warren Merkel]

I thought I'd mention this to the list as it took a while to sort out.  
Fortunately, the resolution was simple.

When powering up the KPA1500 last week, it spit out some 50V power 
supply faults and refused to start up.  In doing so, the amplifier panel 
indicators did some nasty flash-dance flickering before shutting down.   
I power cycled the main power switch on the back of the power supply, 
but still experienced the 50V faults a few more times.   After a few 
minutes of total power disconnection, the amplifier once again powered 
up normally. Everything seemed normal.

However, I didn't notice until I first attempted to transmit, that it 
wouldn't go into PTT.    After a lot of cable swapping and even a switch 
to a KPA500, no cable faults were detected.  The KPA500 happily goes 
into PTT, where swapping back to the KPA1500, the PTT issue resumed.

Yes, I restored the settings from a known-good saved configuration.  
Still no joy.

However, on a whim, I reflashed the firmware using the utility. (Same 
version - 2.58) and the issue vanished.  Apparently, the nasty power up 
flash-n-flicker flipped a few bits in the amplifier's controller program 
space.

And there you have it.

Warren, KD4Z

KPA1500 #143

Boot Block version 1.04