I'd start by opening the box and check the input and output of the regulator, U4, being a LM7805.   Should have ~12V on the input and 5V on the output.  If there is not 12V on the input then check both sides of the diode, D8, which is in series with the 12V input.  Also there is an inductor/choke L9 in series with the 12 volt line to the LM7805.

If the LM7805 does not have 5V on the output, either it has failed or there is a short which is pulling the 5V line to zero. Schematics are available and the rest depends on your trouble shooting skills.

Otherwise, obtain an RA from Elecraft Tech Support.

73

Bob, K4TAX


On 2/14/2019 8:00 AM, Jim Douglas via Elecraft wrote:
Hi All,I have the K line here. I was listening to a QSO and out of the blue my 
KAT500 lost power.I disconnected everything from the KAT500 and then 
reconnected. The power plug has 12 volts so that is not the problem.The KAT500 
was set up to turn on automatically when I turned on the power supply and now 
that does not work anymore.When I press the mode button to turn on the tuner 
that does not work now either. Where do I start looking?Thanks, Jim Douglas  
K2ZF
______________________________________________________________
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
Message delivered to rmcg...@blomand.net

______________________________________________________________
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
Message delivered to arch...@mail-archive.com

Reply via email to